Looking around at the b-places site I found the beautiful medieval sim Aglarond. It's an RP Sim, medieval clothing is required, and no flying unless you're a winged creature.
Of course I managed to find the library right away.
The ballroom is lovely - the stained glass windows are very well done and the place has the aura of twinkling stars inside.
Aglarond has many places to explore. I tried to find my way to the mushroom garden, but that takes a bit of negotiating walkways and rope bridges and walls and such that will have to wait for another time. A very complicated build, there are plenty of areas to explore, it's a lovely sim.