Celtic toponymy from Brythonic *"crüg" 'hill' (Irish "cruach") From tribal name "Dumnonii" or "Dumnones", from Celtic *"dumno-" 'deep', 'world' From Celtic *"dubr-" 'water', *"dubrās" 'waters' (Welsh "dwfr"; Breton "dour") First element is possibly "dun", ' hill fort' (Welsh ddin, 'fort'). First element from Celtic *"duro-" 'fort'; in "Dūrobrīvae", Celtic *"brīwa" 'bridge' Possibly derived from Brythonic *"iska", 'water, fish' and *"leith", 'damp, wet'. From Celtic *"iska" 'water' (Irish "uisce"); second element in "Isca Dumnoniorum" (Exeter) is a tribal name (see "Devon") From Brythonic *"lēd-" [from Celtic *"leito-"] + *"rïd-" [from Celtic *"(φ)ritu-"] = "Grey Ford" From Celtic *"lindo-" 'pool' + Latin "colonia" 'colony'
Insula (Roman city) forum around which the most important public buildings would be sited. Insula (Roman city) An insula (Latin for "island") is a city block in an ancient Roman city plan, i.e. one that is surrounded by four streets. The term was also used for apartment buildings that took up an entire city block. A standard Roman city plan was based on a grid of orthogonal streets and was probably founded on the ancient Greek model of Hippodamus and was used when new cities were established, e.g. in Roman coloniae. The main streets of each city would be the Decumanus Maximus (east–west-oriented)