Which is the best location for tennis holidays in Europe??

Wimbledon.

Avoid scammers, there are lots of rackets going on.

Can you clarify age and ability of participants.
Also time of year?
Are you looking for lessons or just lots of opportunity to play.
What other activities do you want access to? Ar you looking for a full on resort or just a place with on site tennis?
How do you feel about very hot weather (90s and humid) versus playing in cooler weather?
What about budget?

Spain probably

What kind of holiday - playing or attending a major tournament?

some ideas http://www.telegraph.co.uk/travel/de...-holidays.html