The Yawning Portal
A popular pub serving mundane but quality food and libations. It's walls are decorated with a large variety of trophies, ranging from ancient relics, to archeological finds, to taxidermied monsters. Its' popularity and name comes from it's unusual architectural feature. In the center of the dining hall is a wide, crumbling, well-like structure.
Long ago a mage's tower stood at this site, and this ruin is all that remains above ground. Going down below the surface reveals a vast network of halls, vaults, and passages belonging to the tower and the city surrounding it. It was buried thousands of years ago when the current city was built on top of it, and it's mysteries have been forgotten. However, those brave enough to venture in have returned with valuable prizes and artifacts, and it is rumored to hold many more. It is a dangerous trek. The tunnels are labyrinthine and in poor condition, and monstrous creatures call it home. It is not unknown for those that enter to never return.
The proprietor returned from exploring with enough treasure to purchase the plot, build his establishment, and be set for life. He now advertises the Portal as a commercial adventure: he charges 1g to be lowered down to test your luck on finding riches, and 3g to be brought up. Many have taken the challenge and many others visit the pub to witness the challengers.