Most travelers coming from Colombia continue directly on to Ibarra or Otavalo (only two to three hours). If you can't make it those extra couple of hours, though, Tulcán does have a couple of decent places to overnight.
The street food in Tulcán unsurprisingly has a Colombian flavor. By the border, there are plenty of snack stalls and fast-food carts.There's even a nice cafe in the center, air-cooled and wi-fi-enabled.
Drinking & Nightlife
It's an active border town, so there are a few places on the main plaza to quench your thirst, as well as some hotel bars and the ubiquitous karaoke.