user: i'm writing a dungeons and dragons campaign for a couple of friends, given the description of the hellbound city of Dis, could you come up with a couple of cool activities my players could do once they get there? remember that having fun and seeing cool things is the main focus, no matter how serious or absurd a situation can get.

"The City of Dis is incredibly massive. The walls, buildings, and other structures clutter the immense black metropolis and glow at the edges like heated glass. The city is a broken maze of metal ramparts built into miles of steep hillsides and shattered towers framing an endless labyrinth of twisting alleyways.
The air is extremely hot and distorts with the heat as smoke rises from the streets themselves, with the occasional ash or ember drifting through the air.
Most of the buildings are built out of dark stone, climbing for many stories. The architecture is hooked to the corner as the monolithic deep reds, blacks, and grays, nothing belies an exterior that would seem to be welcoming to a traveling pack of people. At the center, visible everywhere in the city, is the Iron Tower, an impossibly colossal and unreachable tower of black iron and lead that stretches for hundreds of miles into the sky before vanishing into the dark, clouded expanse. The Iron Tower is the throne of the archdevil Dispater and stands ever-vigilant over his Iron City of Dis.
The city of Dis is always changing and being rebuilt in accordance with the decree of paranoid Dispater."

assistant: There are several activites in which tourist or business travellers often engaged when arriving to a city:
- Getting information on the city (landmarks and events) from locals. These individual can be officals of the city (guards or clerk of an information desk) and people living in the city (merchants, barkeeps and random pedestrians).
- Getting means of travel (mass transportation tickets or rented carts/horse analoges).
- Securing shelter if they plan to stay for longer period.
- If the crime rate is high in the city then they often hire locals for security and mediation purposes.

user: I was asking you about dungeons and dragons, not business tourism. Try again.

assistant: Of course - I really enjoy these sorts of stories.

Here are some thoughts on entertaining and surprising events.

1. Upon entering the outer city the players encounter a group who ushers them to a hidden building, then attempts to hire them to overthrow Dispater.
2. Several city dwellers try to drive off the party, knowing their presence will bring nothing but suffering.
3. The players hear a loud crash and see a captive Gryphon has escaped, trailing blood it is turning towards its captors for a last stand.
4. A makeshift market is located, selling black market goods at 'too good to be true' prices, what's the catch?
5. The party is captured by Dispaters guards and forced to fight in the arena for the archdevil's amusement.
6. A small voice is heard coming from a storm drain, it's an urchin child, their mother is ill and needs the players to follow.

Of the above options, any could lead to unusual things to see and do. 

The urchin could lead to a forgotten underground city, smashed and buried in the haste to make Dis.
The black market could hold amazing items from foreign lands, one of which could teleport the party to a pocket dimension.
The infamous 'River of Blood' can be seen streaming from the tower gates, is it really blood? So much blood...

Let me know if any of those options sound interesting.