While there isn't a single formal "collective noun" for tourists in the way we have a "pride" of lions, several terms are used depending on the context and the observer's perspective. In a neutral or industry-focused setting, they are simply referred to as a group, a party, or a contingent. In more colorful or descriptive language, you might hear them called a throng, a horde, or even a flock, which alludes to the way tourists tend to move together behind a guide. In the travel trade, a group of tourists traveling together on a pre-arranged itinerary is often called a tour party or a package group. More colloquially, and sometimes with a touch of local wit, they are referred to as a sightseeing party. In the digital age, those who move specifically to document their travels might be called a collective of explorers. Ultimately, the term used says as much about the environment as it does about the people; in a busy museum, they are a crowd, but to a specialized tour operator, they are a delegation or a cohort of travelers embarking on a shared journey of discovery.