You must have gone at a quiet time. Avebury can be absolutely heaving in the Summer and on the traditional pagan quarter days.

It also has a pub, a restaurant, a gift shop, a museum founded by a marmalade magnate, and if you're really rich you can buy one of the houses inside the circle.

Generally a happier experience than Stonehenge.

If megalithic rocks are your thing there's also the nearby West Kennet Longbarrow, which is far more likely to be deserted, especially at night, although if you go on the quarter days (nights) you'll probably meet weirdly-dressed people lighting candles and throwing spells around.