But monuments remain which show that the Druids were not in this respect wholly confined to groves.

They had also a species of building which in all probability was destined to religious use.

This sort of structure was, indeed, without walls or roof.

It was a colonnade, generally circular, of huge, rude stones, sometimes single, sometimes double, sometimes with, often without, an architrave.

These open temples were not in all respects peculiar to the Northern nations.