Sylvan Dam was a splash dam and small settlement located around the Riverside/Pontaria region. As the river it was on was too shallow for normally floating timber down the river for charcoal production, Sylvan Dam was built to raise the water levels and, when high enough, was opened, sending a wave of water and timber further down the river to its destination.
As the location was mostly for dam workers, it didn't have any real establishments: it's equivalent of a tavern was simply a small shack with a leaky thatched roof and some tables and chairs. Nearby, there's an obelisk with words carved into it commemorating the time the Prophet Lebioda gave a speech there during Birke1133.
In 1245, Geralt passed through here with Addarion Bach to get to Wiaterna, a harbor that was about an hour's brisk walk from the dam.