Alnwick is located just off the A1 in Northumberland, so travelling by car is a good option. Though for those of you travelling from Cardiff and further afield then the journey takes around 6 hours. So please make sure you take plenty of breaks and ideally share the driving between multiple people.
Alnmouth is a regular stop on the London to Edinburgh train. The journey from London is ~3 hours and 30 minutes and then a short taxi/car journey to Alnwick from Alnmouth. For those of you considering taking the train from Cardiff, it is definitely possible and is a similar time to driving (6 hours and 10 minutes). Note that the journey from Cardiff will involve a transfer at Birmingham New Street or Manchester Piccadilly.
Newcastle does have an airport that has a few domestic flights, so for those who would rather fly, then it is an option. Note that the flight will only get you to the outskirts of Newcastle. You will have to make alternative arrangements for the remainder of the journey to Alnwick.
This is a nice hotel but slightly further from the centre of Alnwick.
Cheap accommodation option for Alnwick. Slightly further from centre of town and venue
Hostel accommodation for larger groups wanting to get a bargain. It is located near the centre of Alnwick
Please consider booking an Airbnb for larger groups - there are loads of great places to stay in Alnwick and the surrounding villages