In the meaning "to", used with place names that start with a definite article. Place names that do not start with a definite article take the preposition go instead.
Because this term originated as a verbal expression, the noun it governs is in the nominative case in the standard language, as can be seen by its mutation effects on masculine singular nouns after the definite article: consonants are not mutated (e.g. go dtí an capall (“toward the horse”)) and vowels take t-prothesis (e.g. go dtí an t-uisce (“up to the water”)). Colloquially, however, the dative may also be found, e.g. go dtí an gcapall/chapall (“toward the horse”), go dtí an uisce (“up to the water”).