Backstory: Whenever I travel and stay in an AirBnB I'm always hopeful that the owner will offer to show me around the city. There's nothing more authentic than a true local giving you a tour.
The Idea: AirBnB tours.
Deep Dive: You would coordinate with local AirBnB hosts and offer local tours for their AirBnB clients. You could build a quick survey and based on their answers, you would know what attractions to show them. You could offer a small kickback to the AirBnB host and as you scale you can coordinate with multiple hosts to provide tours to small groups.
Validation: Local tours have been around for years.
Monetization: You would charge a small fee per customer for the tour, optionally you could offer to do it for free and work for tips. As you partner with more AirBnB hosts, you can start to scale out and hire some tour guides.