My DC are now late teens and we enjoyed our first child free holiday for 18 years this year.
When DC hit 10, we did more adventurous holidays with them rather than British bucket and spade type:
Thailand (family adventure holiday with Exodus - Bangkok, River Kwai, Errawan waterfalls, Chaing Mai hill tribe stay, Koa Samet beach stay)
Egypt (family adventure holiday with Explore- Cairo pyramids, Aswan, Sailing up the River Nile on a Felucca for 2 days, Luxor Valley of the Kings etc, Snorkelling in the Red Sea Hurghuda 3 days)
New York and Washington DC
Italy (Venice, Verona, Rome and Pompeii)
Real Family Holidays - Pembrokeshire, Wales
Istanbul (4 days stop over) and Cape Town (10 days- Climbing Table Mountain, Robben Island, Cape Point, Boulders Beach, Safari for 2 days etc)
City breaks- Berlin, Amsterdam, Krakow