This paper investigates the lexicalisation of geographical nouns in Latin and Ancient Greek using a nd Ancient Greek using a diachronic, multi-genre corpus (8th cent. BCE – 2nd cent. CE) and Large Language Models for Word Sense Disambiguation. We focus on two main aspects: the onomasiological question of which words encode core geographical concepts, and the semasiological distribution of senses across lemmas. Across both languages, city-related concepts are the most frequently expressed, but Greek shows a stronger focus on maritime terms, whereas Latin favours concepts related to land. Semasiologically, Latin shows clearer evidence of semantic change over time (e.g., ’citizenship’ - ’city’, aequor ’flat surface’ - ’sea’), while Greek displays more gradual or distributed shifts. These results show that computational annotation enables cross-linguistic and diachronic analysis of spatial semantics, allowing us to compare the frequency of concepts across languages, genres, and periods, and to track when semantic change occurs and how core concepts evolve over time.