Cool historical site. Nice view of city from top. Nice interpretive content explaining history of…read moretower. Price (30 euros) is too high (but Isanbul's tourist attractions in general are priced quite high) but Museum Turkey pass covers site. Definitely a site worth checking out.

Originally commissioned by Byzantine emperor Justinian the Great in the 6th century as a…read morelighthouse, it would then serve as a strategic watchtower, later a dungeon, now it's a museum. It's the iconic symbol of Istanbul. I think this might be the only UNESCO World Heritage Site I couldn't give 5 stars to, and that's because they don't keep to posted hours. It's sometimes just closed and there's no way to find out without coming here. Some reviews say to visit if nearby, but there are plenty of reasons to be in the area anyway, crossing the bridge over the Bosphorus, climbing up to or back from Pera, and the shopping right around here. Plus, you can meet some nice cats. The view from the top is spectacular, the climb up a little less fun. It's one of the oldest structures surviving in Istanbul, so even if entry is closed, it is well worth it to get up close and look at it from all around. The aggressive guides are a nuisance and you certainly don't need them.