Except you'd be more likely to say "Tourists go to the theater." Leaving the article out casts the sentence in a generalized frame of reference, so the verb should reflect what tourists generally do. If you use the present continuous, then you should use the article.
You can make a general statement that tourists go to the theater. You can also make a general statement that in downtown, it's 8:00 p.m., and tourists (not the tourists) are going to the theatre. "The" is not necessary unless you're referring to a particular group of tourists.
It's not incorrect, but this construction implies a general statement, not a particular instance of tourists going to the theater. So in Russian, that's more likely, Туристы ходят в театр. If you're emphasizing "the tourists," a particular group of tourists, then in Russian you'd likely use a noun determiner like эти туристы or те туристы ходят в театр, still a general statement about them habitually going to the theater.
But I have to say, tourists without 'the' is quite unnatural in spoken English too. I would say "THE tourists are going to THE/A theatre" sounds the the most natural in spoken English. Unless we want to generalise or speak as a cliche, such as "Tourists go to theatres" (here both the tourists and theatres have no articles), but in this case both should be in plural form... In my case, it can be use as a question of choice. Say, from one tour guide to another, "What are the tourists doing after lunch, shopping or theatre?" Answer, "The tourists are going to theatre".
someone knows the difference between "bosli" and "blisko" - The two words mean both "near/close/nearby". Sorry for my writing but I do not have russian characters in the keyboard. Is it possible to use them indifferently or is a there a difference? Thanks for an explanation- Lorenzo46