As an encouraging note, I was invited to visit the tower at LPL just through being a member here!
I have been 3 times in the past few months.
Personally, I always take a little "gift" as a thanks to the chap who gives up his time after the end of his shift to show us around. And for his colleagues to enjoy too.
A couple of bottles of wine here and there, box of assorted biscuits, chocs, that kinda thing.
It's not compulsory and not even expected, but I feel I need to show some appreciation.
Good luck with a visit and future career.
Cliff