The simplest arrangement is to have one convenient venue for all your events. However, this may not be possible, e.g. if the evening venue is not available at lunch time. Also, it may not be advisable to stick to one venue if people generally live in a different part of the city to that where the university is located.
Lunch venues need to be on or near the university, whereas an evening venue ideally wants to be close to where the students live.
An International Event would need to be in or close to the venue for the Evening Event if you expect guests to go from one event to the next.