I was going to suggest Prague...
http://www.expedia.co.uk/pub/agent.dll?qsfr=cm fd&itid=&itdx=&itty=&ecid=
I've stayed here at the 987 Design, fab hotel with cheap bistro nearby, everything in walking distance.
If booked separately: �611.49
Expedia discount for booking together:
-�21.95
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Sub-total for this trip: �589.54
Average price per traveller: �294.77
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Insurance for all travellers: �26.00
Total price for this trip: �615.54
Included:
Items selected, taxes, & service fees.
Insurance was added for benefit when travelling. You can remove the insurance option below.
Flight: 2 return tickets
07:25 Depart London (LCY)
Arrive Prague (PRG) 12:00 Sat 16-Aug
Duration: 3hr 35min Swiss International Air Lines 485 / 1460
Connect in Basel (BSL)
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18:05 Depart Prague (PRG)
Arrive London (LCY) 21:35 Tue 19-Aug
Duration: 4hr 30min Swiss International Air Lines 1473 / 440
Connect in Geneva (GVA)