St Pancras International Rail Station is set in the heart of Central London with more underground connections than any other London station. One of the main services is the Eurostar line, which can have you in either Paris or Brussels in about 2 hours. Right across the street is Kings Cross Underground Tube hub.
Have a great meal within the station at either Betjeman Arms or St. Pancras Grand or just just have a drink at The Champagne Bar.
The Premier Inn 2 blocks away was an excellent, clean and inexpensive hotel with a fantastic restaurant called The Fellow right next door.