Per organizers UK-based SE1 Media Limited, the Digital Tourism Think Tank (DTTT) is an initiative that "aims at providing thought leadership to the tourism industry in digital marketing best practice."
The DTTT 2018 Destination Challenge is: "How can we overcome the challenge of overcrowding in tourism hotspots and spread the value of tourism wider?"
Applicants are invited to compete for "unique and exclusive prizes" by coming up with "real solutions." Participation is free. Anyone involved in tourism, in industry or academia, is invited to field a team. Judging criteria are "Strength, Viability, Approach and Longevity".
Event is scheduled to run from 8 AM to 4:30 PM 7 November 2018 in conjunction with the WTM trade show.
Here is the participant application form.
Sounds interesting. Overtourism is definitely a 2018 problem. (See this article on overtourism.) I look forward to seeing what comes out of this competition.