diff --git a/langs/themes/cy.json b/langs/themes/cy.json
index 0967ef424..5070253e4 100644
--- a/langs/themes/cy.json
+++ b/langs/themes/cy.json
@@ -1 +1,448 @@
-{}
+{
+    "advertising": {
+        "title": "Hysbysebu"
+    },
+    "charging_stations": {
+        "title": "Lleoliadau Gwefru"
+    },
+    "cyclestreets": {
+        "layers": {
+            "2": {
+                "name": "Pob stryd",
+                "title": {
+                    "render": "Stryd"
+                }
+            }
+        }
+    },
+    "cyclenodes": {
+        "layers": {
+            "1": {
+                "title": {
+                    "mappings": {
+                        "0": {
+                            "then": "Nod seiclo <strong>{rcn_ref}</strong>"
+                        }
+                    }
+                },
+                "tagRenderings": {
+                    "node-expected_rcn_route_relations": {
+                        "freeform": {
+                            "placeholder": "e.e. 3"
+                        }
+                    },
+                    "node-rxn_ref": {
+                        "freeform": {
+                            "placeholder": "e.e. 1"
+                        }
+                    }
+                },
+                "presets": {
+                    "0": {
+                        "title": "nod seiclo"
+                    }
+                }
+            },
+            "0": {
+                "name": "Cysylltiadau nod i nod",
+                "title": {
+                    "render": "Cyswllt nod i nod"
+                }
+            }
+        },
+        "title": "Rhwydweithiau Nod Seiclo"
+    },
+    "maps": {
+        "title": "Map o fapiau"
+    },
+    "walls_and_buildings": {
+        "title": "Waliau ac adeiladau"
+    },
+    "atm": {
+        "title": "Peiriannau Codi Arian"
+    },
+    "circular_economy": {
+        "layers": {
+            "5": {
+                "override": {
+                    "=name": "Siopau ail law"
+                }
+            }
+        }
+    },
+    "benches": {
+        "shortDescription": "Map o feinciau",
+        "title": "Meinciau"
+    },
+    "cafes_and_pubs": {
+        "description": "Tai coffi, tafarndai a bars",
+        "title": "Caffis a thafarndai"
+    },
+    "climbing": {
+        "layers": {
+            "0": {
+                "override": {
+                    "tagRenderings+": {
+                        "1": {
+                            "mappings": {
+                                "3": {
+                                    "then": "Dim ond aelodau o'r clwb"
+                                },
+                                "0": {
+                                    "then": "Ar gael yn gyhoeddus i unrhyw un"
+                                },
+                                "2": {
+                                    "then": "Dim ond cwsmeriaid"
+                                }
+                            },
+                            "question": "Pwy sy'n gallu mynd yma?"
+                        }
+                    }
+                }
+            },
+            "2": {
+                "override": {
+                    "=presets": {
+                        "0": {
+                            "title": "siop drwsio esgidiau"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "drinking_water": {
+        "title": "Dŵr Yfed"
+    },
+    "elongated_coin": {
+        "title": "Gweisg Ceiniog"
+    },
+    "facadegardens": {
+        "layers": {
+            "0": {
+                "tagRenderings": {
+                    "facadegardens-description": {
+                        "render": "Rhagor o fanylion: {description}"
+                    },
+                    "facadegardens-edible": {
+                        "mappings": {
+                            "0": {
+                                "then": "Ceir planhigion bwytadwy"
+                            }
+                        }
+                    },
+                    "facadegardens-plants": {
+                        "mappings": {
+                            "1": {
+                                "then": "Ceir planhigion blodeuog"
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "food": {
+        "description": "Bwytai a bwyd brys",
+        "title": "Bwytai a bwyd brys"
+    },
+    "healthcare": {
+        "layers": {
+            "5": {
+                "override": {
+                    "=presets": {
+                        "2": {
+                            "title": "optegydd"
+                        },
+                        "1": {
+                            "title": "siop gymorth clyw"
+                        }
+                    }
+                }
+            }
+        },
+        "title": "Gofal Iechyd"
+    },
+    "hotels": {
+        "title": "Gwestai"
+    },
+    "indoors": {
+        "title": "Dan Do"
+    },
+    "icecream": {
+        "title": "Hufen Iâ"
+    },
+    "kerbs_and_crossings": {
+        "title": "Cyrbiau a chroesfannau",
+        "layers": {
+            "1": {
+                "override": {
+                    "=presets": {
+                        "0": {
+                            "title": "croesfan"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "mapcomplete-changes": {
+        "layers": {
+            "0": {
+                "filter": {
+                    "11": {
+                        "options": {
+                            "0": {
+                                "question": "Pob platfform"
+                            },
+                            "2": {
+                                "question": "Gwnaed ar y we"
+                            },
+                            "1": {
+                                "question": "Gwnaed ag Android"
+                            }
+                        }
+                    },
+                    "4": {
+                        "options": {
+                            "0": {
+                                "question": "Gwnaed cyn {search}"
+                            }
+                        }
+                    },
+                    "5": {
+                        "options": {
+                            "0": {
+                                "question": "Gwnaed ar ôl {search}"
+                            }
+                        }
+                    },
+                    "2": {
+                        "options": {
+                            "0": {
+                                "question": "Gwnaed gan gyfrannwr {search}"
+                            }
+                        }
+                    },
+                    "6": {
+                        "options": {
+                            "0": {
+                                "question": "Cymraeg (cy) {search}"
+                            }
+                        }
+                    }
+                },
+                "tagRenderings": {
+                    "version": {
+                        "render": "Gwnaed gyda {editor}"
+                    },
+                    "locale": {
+                        "render": "Iaith y defnyddiwr yw {locale}"
+                    },
+                    "platform": {
+                        "mappings": {
+                            "0": {
+                                "then": "Gwnaed ar y we"
+                            }
+                        }
+                    },
+                    "show_changeset_id": {
+                        "render": "Grŵp newid <a href='https://openstreetmap.org/changeset/{id}' target='_blank'>{id}</a>"
+                    }
+                },
+                "title": {
+                    "render": "Grŵp newid am {theme}"
+                },
+                "description": "Dangos pob newid MapComplete"
+            }
+        }
+    },
+    "notes": {
+        "title": "Nodiadau ar OpenStreetMap"
+    },
+    "onwheels": {
+        "layers": {
+            "6": {
+                "override": {
+                    "=filter": {
+                        "0": {
+                            "options": {
+                                "0": {
+                                    "question": "Pob math o gwrb"
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "osm_community_index": {
+        "title": "Mynegai Cymunedau OSM"
+    },
+    "postal_codes": {
+        "layers": {
+            "0": {
+                "title": {
+                    "render": "Cod post {postal_code}"
+                },
+                "tagRenderings": {
+                    "postal_code": {
+                        "render": "Y cod post yw {postal_code}"
+                    }
+                }
+            },
+            "2": {
+                "title": {
+                    "render": "Neuadd y Dref {name}"
+                }
+            }
+        }
+    },
+    "scouting": {
+        "title": "Grwpiau Sgowtio"
+    },
+    "stations": {
+        "layers": {
+            "16": {
+                "name": "Byrddau Ymadael",
+                "title": {
+                    "render": "Bwrdd Ymadael"
+                },
+                "presets": {
+                    "0": {
+                        "title": "bwrdd ymadael"
+                    }
+                }
+            },
+            "3": {
+                "name": "Gorsafoedd Trên"
+            }
+        },
+        "title": "Gorsafoedd Trên"
+    },
+    "sports": {
+        "layers": {
+            "4": {
+                "override": {
+                    "presets": {
+                        "0": {
+                            "title": "siop chwaraeon"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "sport_pitches": {
+        "shortDescription": "Map sy'n dangos caeau chwaraeon",
+        "title": "Caeau Chwaraeon"
+    },
+    "street_lighting": {
+        "layers": {
+            "2": {
+                "name": "Pob stryd"
+            }
+        },
+        "title": "Golau Stryd"
+    },
+    "transit": {
+        "title": "Ffyrdd Bws"
+    },
+    "trees": {
+        "description": "Mapiwch bob goeden!",
+        "shortDescription": "Mapiwch bob goeden"
+    },
+    "toilets": {
+        "description": "Map o doiledau cyhoeddus",
+        "title": "Toiledau Cyhoeddus"
+    },
+    "vending_machine": {
+        "title": "Peiriannau Gwerthu"
+    },
+    "walkingnodes": {
+        "layers": {
+            "1": {
+                "tagRenderings": {
+                    "node-expected_rwn_route_relations": {
+                        "freeform": {
+                            "placeholder": "e.e. 3"
+                        }
+                    },
+                    "node-rwn_ref": {
+                        "freeform": {
+                            "placeholder": "e.e. 1"
+                        }
+                    }
+                },
+                "title": {
+                    "render": "Nod cerdded",
+                    "mappings": {
+                        "0": {
+                            "then": "Nod cerdded <strong>{rwn_ref}</strong>"
+                        }
+                    }
+                },
+                "presets": {
+                    "0": {
+                        "title": "nod cerdded"
+                    }
+                }
+            },
+            "0": {
+                "name": "Cysylltiadau nod i nod",
+                "title": {
+                    "render": "Cyswllt nod i nod"
+                }
+            }
+        },
+        "title": "Rhwydweithiau Nod Cerdded"
+    },
+    "waste": {
+        "title": "Gwastraff"
+    },
+    "waste_basket": {
+        "title": "Biniau Sbwriel",
+        "shortDescription": "Map o finiau sbwriel"
+    },
+    "shops": {
+        "title": "Siopau"
+    },
+    "postboxes": {
+        "title": "Map Blychau Post a Swyddfeydd Post"
+    },
+    "education": {
+        "title": "Addysg"
+    },
+    "openlovemap": {
+        "layers": {
+            "2": {
+                "override": {
+                    "=presets": {
+                        "0": {
+                            "title": "siop erotig"
+                        }
+                    }
+                }
+            },
+            "6": {
+                "override": {
+                    "=presets": {
+                        "0": {
+                            "title": "sinema erotig"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "campersite": {
+        "overrideAll": {
+            "tagRenderings+": {
+                "0": {
+                    "question": "Pwy sy'n rhedeg y lleoliad hwn?"
+                }
+            }
+        }
+    }
+}