I have answered this question in Orberg’s Exercitia Latina:
Cur magnae naves Roman adire non possunt?
…with…
Pars Tiberis quae prope Romam nimis parva est. itaque naves magnae ad huic loco navigare non possunt.
Does it look OK?
“Pars Tiberis quae prope Romam est nimis parva est.” or simply “Pars Tiberis prope Romam nimis parva est.”
“Itaque naves magnae ad hunc locum navigare non possunt.” or “Itaque naves magnae huc/illuc navigare non possunt.”
“ad” requires nouns in the accusative case.
Thanks Thesaurus.
Er, no it isn’t… it’s still the wrong case, though.
If on the off chance you need to use the ablative of “this place” (which would be common with prepositions such as “in”), that would be “hōc locō”. But “ad” does always take the accusative, not the ablative, and remember that prepositions can never take the dative or any other case besides accusative and ablative.
Oops. For some reason I was thinking of “huc” when I wrote that.