Day trip is a great idea! Adults like it as much as children do. Choose the theme. For ex. in The Museum of Ancient Iran you choose one exposition or one historical period. Surely such trips must be thoroughly prepared. I skip organizational problems, it’s not a problem with the adults, just make sure that you gave all the instructions in advance.
After you have chosen the theme, choose the final product that you would like to have:
1. Will it be a written text that they need to write after your day trip? In this case decide in advance what would be the evaluation criteria for this assignment. Depending on their level it could be a description of what they saw (the lower level). You can ask more proficient language learners to write a summary in English of the information given by the guide of the museum (who speaks native language, of course). If you have advanced level students, give them the theme that they need to explore supporting their arguments with the clues they’ll find at the Museum. Make this writing activity more interactional, asking them to work in small groups of 4, so that they could exchange their opinions and help each other, asking questions at the Museum. You can also make this activity a cooperative activity using a jigsaw research, when the group has one theme per group, but each member of the group will write a text only about one aspect of the main theme.
2. Or you would like to make an oral activity. Ex. You divide them in groups of 4. Each of the students will have a theme to prepare in advance. They need to be ready to act at the museum as tour-guides for the three other participants who would be representing English tourists in this activity, who need to ask questions etc. Actually, this one is my students’ favourite.
3. Do some active learning activity. Provide students with a vocabulary list, textual information on the theme. Ask them to make up a quiz. You can ask them to make 2 quizzes: a preliminary one (in written or oral form), before they go to the museum and final one (a written quiz the next lesson after the trip to check other students’ comprehension, attention, what they remembered or not). Do not forget the special rule to speak only English at the museum, even in ordinary situations between students.
I assure you it’ll be a real fun for your students.
I wish you and your class a nice day trip.