Where to next is the question?

So fellow travellers I have come to the point where I'm at a cross-road regarding on where to go to next.  It has to be in Europe and I have 4 days, so nothing like the Maldives or Bali, although they're both in my bucket list 😜I also want to stay on a budget, so nothing  too luxurious thanks.  I've been thinking of London, Brussels or Praga.

Your views will be most welcome 😉