You would go 'to' a restaurant, or arrive 'at' a restaurant... but you wouldn't arrive 'to' a restaurant. This might be a correct translation from Portuguese but it isn't grammatically correct in English.
This has been fixed by DL. Now the preferred answer is "They arrive at the restaurant."
Wouldnt this be more correct as "They come to the restaurant" or "They arrive to the restaurant"? I would think "arrive at" would be "Eles chegam no restaurant"
Is that because no is a merging of 'em o' and 'ao' is a merging of 'a o' to the?
Attention: the only correct form is "chegar à/ao". I included "na/no" because everybody uses it in day-to-day conversation.
check out "shatto" above. He is correct. We arrive at a place and we go to a place.