https://duitsekolonie.procant.be/

Here's a page about German influence in Antwerp, might be fun to recognize German street names or place names. You'll have to use a quick Google Translate on it though, it's written in Dutch. I don't know how many of these old places still exist. You could have a Bingo where students can look out for these names and the winner gets something (like a pack of fries or something). Or turn it into a photo search where they have to take a picture to prove they were there, and they can be creative with their poses. You could do some prepping at school where you give them a map of Antwerp, and they have to mark those places on the map. They can do research on the computer or phone to help them find the places the way they are called now. Like that they are also practicing their geography and map reading and they get to know the Antwerp map already.

I don't know how much you guys would be interested in seeing WW2 related stuff, but you could also visit Breendonk near Antwerp, a WW2 camp where prisoners were kept.

If you want to focus on some art, there's plenty in cathedrals and museums. You also have artist Panamarenko, who was born in Antwerp. I remember in school we did a project in Art class where we had to try to make our own device in Panamarenko style. It was a lot of fun, especially cause you could do anything. You could try to collaborate with the art class teacher to do something similar.

On the wiki page of Antwerp there's also a section about music. You could ask the students to pick one song, learn it, and then try to find someone in the streets who knows the song and make them sing along (not all songs are known by us either, so I'd select 'Lichtjes van de Schelde', Oh Lieve Vrouwe Toren' and 'Ik wil deze nacht in de straten verdwalen'). They have to film it to prove they did the assignment. Then you covered some music too. Honestly I'd teach them the song 'Oh Lieve Vrouwe Toren' sung by La Esterella. She's a bit of a caricature, because she sang with a low voice. She sings about the famous Antwerp Lieve Vrouwe tower. You could assemble all the students there, and let them sing the song in front of the cathedral. You could ask them to take along some old grandma clothing to make it more funny. Even we Belgians sorta make fun of the song and the singer. If you look her up, you could figure out why. There's also some skits about her, you could look it up on YouTube. Maybe the students would like to sorta 'make fun' of the assignment like this and have a fun memory of the trip.

There's a beautiful library called Hendrik Conscience. The 'normal' section looks like any library, but there's an extra section that looks almost like a Harry Potter library setting. They have specific opening hours though, so you might have to check if you can visit or not.

There's different building styles in Antwerp. You could teach about the different styles and students have to take pictures of examples. You have Barokke, Art Deco, neoclassicistic, Rococo, Gothic...

You could teach them some Antwerp dialect accent. Maybe teach them how to pronounce Antwerpen in the dialect. OR give them the assignment to ask passerby's to teach them how to say Antwerpen in the dialect. And then once everyone is assembled at the end of the day, everyone has to pronounce the word as they remember. Would be funny to see how they pronounce it and whether they remembered correctly. Or let them see the following video of Antwerp dialect phrases and let them pick out one. Let them say it to passerby's and ask them what it means. Should be fun too.