Revelation Online is not safe to explore. It’s a dangerous place, and there’s battle at every turn. But Sidus Ur is one of the few places that manages to keep battle almost entirely confined to outside of the city walls. Sure, there are people murdering critters in the city, but that’s still better than you’re going to find on the other side of the walls, so it might as well be peaceful.
There’s also the daily pirate quest in which a whole lot of people fight over hoarded treasure, but again, that’s a minority. Hardly ever happens. It’s safe enough.
If you don’t want to fight people over pirate bounty or just kill local wildlife, you’ll find a peaceful city full of vendors and resources. You can also get a daily blessing from the Wishing Tree, giving you even more reason to hop to the city and stock up before heading back outside to greater dangers.
Source: Official Site