Can't give you any specific suggestions, but wanted to make sure you got at least some general help. Hopefully a local or someone nearby will chime in later with some more specific suggestions.
Here are some ideas and/or web resources you might want to check out (in no particular order):
1. Obviously there are some things on the Purdue campus that they can check out (beyond the "usual suspects" of a campus visit). I'm presuming they've checked out the Purdue webpage, but just in case they haven't, here's a link to the "visiting" page which includes a link to an on-line visitor's guide:
2. Prophetstown State Park and the Tippecanoe Battlefield are both nearby.
3. Here's a link to the Tippecanoe County "visitor's" page which has some links to other resources:
4. Here's a link to the actual Tippecanoe County Convention & Visitor's Bureau page:
5. Lastly, for eating ideas, here's a link to the Urbanspoon page for the Lafayette area:
Urbanspoon is my "go to" restaurant site and most of Indiana (and it appears the Lafayette area) has the critical mass to make this sort of crowd-sourced website worthwhile.
I think between the information on the above pages and/or pages they link to you'll have a pretty good list of things to see/do.
Beyond that . . . there's not really much between Indy and Lafayette/West Lafayette - at least not on the direct route (I-65) - it's only about 60 miles and there is really only 1 small town on the way (Lebanon). Thus, in terms of things "on the way" I'd suggest either things in Indianapolis or taking a non-direct route (even then there really isn't that much on the way).
Don't have time to go into all the things Indy offers right now, you might check out the Indy forum for ideas. I'll try to post a few other ideas later. On that note do they have any particular likes/dislikes? This will allow me (and others) to tailor suggestions that are more likely to interest them.
Hope this helps,
Hi. Huntlawoffice has offered some excellent resources and links for your friend to check out. Is this an informal visit or is it part of a more official program? If it's an informal one, I would strongly suggest that they contact the department of the major(s) that they are interested in and to talk to some of the professors. If they are interested in certain activities or programs - like the Marching Band or athletics, have them contact someone in that area to learn more about it. These meetings give the potential student a better idea of what's available and the "fit" for them.
There are also campus tours out of the Campus Visitor's Center on Northwestern Avenue. For sure, visit Neil Armstrong Hall which has some space program exhibits. Purdue graduates make up the largest group of astronauts, including the first and last astronauts that visited the moon.
They can also check the Purdue website to see if there are any athletic events going on while they are there. It hasn't been the best year for Purdue basketball, but a game can still be fun to go to.
Hope that helps. My son graduated from Purdue last year and is finishing up his Master's there this year. Happy to answer any other questions. BB