Here are some great places for day trips out of London. Station Guide.
Bath, NR: Paddington Station
Brighton, NR: Victoria Station
Brussels, NR: St Pancras Station
Cambridge, NR: King's Cross Station
Canterbury, NR: Charing Cross Station
Hampton Court, NR: Waterloo Station
Leeds Castle, NR: Victoria Station
Lewis, NR: Charing Cross Station
Moreton-in-Marsh, NR: Paddington Station
Oxford, NR: Paddington Station
Paris, NR: St Pancras Station
Rochester, NR: Charing Cross Station
Rye, NR: Charing Cross Station
St Albans, NR: King's Cross Station
Stonehenge, NR: Waterloo Station
Stratford-upon-Avon, NR: Marylebone Station
Winchester, NR: Waterloo Station
Windsor Castle, NR: Waterloo Station
York, NR: King's Cross Station