She gives him a quick smile, nods, and then leads him into the cave.

There are giant cave spiders, but the giant cave spiders aren't much of a threat to two accomplished Dalish hunters with bows. Once or twice, Shiral warns Tamlen not to step on a particular square of floor - apparently they're not the only ones who have set traps here. And it is indeed a proper ruin - the walls and floor and ceiling are all finished stone, no rough cave walls to be seen.