I am studying abroad in Cardiff wales next semester and am flying into London. I will have about a week and a half to get from London and Cardiff. I have been to London before and I dont need to see everything there but I will probably spend 3 days there adjusting to jet lag. If any one has any ideas, let me know!
Are you going to be driving or using public transport?
Here's a cut-'n-paste from Rick's Itinerary list:
3 days: London
5 days, add: Bath and nearby sights (take a minibus tour or choose some combination of Stonehenge, Avebury, Wells, Glastonbury, and Salisbury)
7 days, add: Cotswolds
Plus (choose from the following)...
Cambridge, Oxford, Blackpool, Coventry, Portsmouth, Brighton, Canterbury, or Dover
It takes 2 hours by train to get from London (Paddington) to Cardiff with trains usually very 30 minutes. However, on weekends, you might well find trains take a longer route over the next 3 years as the entire line is being electrified. If you buy tickets on the day, fares will be expensive so you should pre-book up to 12 weeks out - with fares rising over that period.
www.nationalrail.co.uk for schedules & fares or www.firstgreatwestern.co.uk to make bookings. However, if you are within the age range, I would certainly think about buying a young persons railcard:>http://www.16-25railcard.co.uk
The cheapest way to get from London to Cardiff is www.megabus.com
If landing at Heathrow, you could take a shuttle bus to Reading and then the train direct to Cardiff as this saves you from going into London. www.railair.com
Someone has suggested that you visit Bath en-route. Beware that accommodation in Bath can be expensive. Trains run hourly between Bath & Cardiff and are relatively cheap - even paying on the day. As the journey is only about 1 hour, you might well wish to do this as a day trip from your cheap student accommodation in Cardiff. Oxford may well be more worthwhile doing en-route but is still daytrippable from Cardiff. (If buying rail tickets between the two places, it is usually cheaper to split the tickets at Didcot and sometimes Swindon as well). http://www.splityourticket.co.uk
Mostly walk around, go to the Globe theater for Shakespeare and the National Theatre if that appeals, visit the Tate, see the changing of the guard if you haven't, walk by Buckingham, go into the Houses of Parliament and see if you can sit in on a session, visit Westminster Abbey, have tea at Brown's or Claridge's if you can afford it, otherwise find somewhere sweet. Eat fish and chips and go to Portabello Market, walk through Hyde Park.
While you're in Cardiff, don't miss all the castles Wales has to offer - it's not a big country and you can drive from end to end in a day. It's worth renting a car to go to the Mumbles, which is close to Dylan Thomas's home, or further to St David's and up to Aberystwyth (few hundred miles), I haven't been to Cardiff in some years and I know it's changed since I used to have a half pint at the Angel in the 1960s and 70s, so you're on your own there -- except that Cardiff Castle will still be as regal. There used to be a parking lot in the moat and parts of the castle were used as classrooms for art students The area surrounding Cardiff is also worth seeing -- the town of Llantwit Major is part of the Arthurian Legend, Ogmore Castle is a delightful ruin with a stepping stone path across the Ogmore River behind it. It's close to Dunraven beach, which is a crescent of sand and huge boulders at the base of tall cliffs that run up and down the coast. Ewenny Priory is also out that way as well as the oldest pottery in Wales, Ewenny Pottery. To understand the Welsh, don't miss some of the celebratory places -- Porthcawl, Barry Island. Just find a car (or a bike) and tour around. You're sure to be surprised. Make sure to make a stop in the Fox & Hounds or the Farmer's Arms (or both) in the village of St Bride's Major just outside Bridgend, a nice market town where I assume you can still see farmers selling sheep on Tuesdays. Enjoy yourself - the Welsh are a hospitable crowd and will likely want to buy you a drink and hear your story. Also, I dp hope you like to sing...
I am assuming (maybe incorrectly!) that as you are a student, you are under 25. If so, as you have a week spare, I would cover other ground that is not easily covered from Cardiff as day trips. Forget Bath as this is doable in a day from Cardiff and it is the second most expensive place to stay after London, (I am assuming cost will be a factor).
I would spend a few days in Brighton - easily reachable from London by train or bus and there is everything from coastal walks to history to trendy shopping to great nightlife.
With a week to spare, you could go further north but without knowing what kind of thing you want to do, it is difficult to advise.