Offer from UCL in meantime, do they do applicant days?
From the UCL website:
Applicant open days and selection events
If you’re a UK-based applicant, you may be invited to attend an applicant open day and/or selection event. We want to meet you, get to know you better and give you a feel for what UCL is like as an institution and what it might be like studying here. If you live overseas, or would have a difficult journey to get to UCL, you would usually be exempt from an interview or compulsory open day (except in the case of Medicine applicants). All the same, we strongly encourage you to visit UCL before making a decision on which universities to apply to.
www.ucl.ac.uk/prospective-students/undergraduate-offer-holders/your-offer-what-happens-next/step-1-open-days-and-campus-tours
Re Birmingham, as with everywhere else where DS1 and DD held offers, they ask whether the applicant wants to bring (one or two) guests. There are other things to do on site (the Barber Institute gallery and the Museum of Geology), so you may not want to go to all the 'parent' things. Although we did get a free lunch on DD's applicant day, as it was a full day, not just a.m. as DS1's was.