Rosa I think you've guaranteed now there will me a major heatwave when you get to the UK :o
We took a ferry from Ancona to Split, then went to a camping an hour or so's drive north of Split, it was lovely, super clean and shady, we had the sea about 15m from our tent. Rocky beach but the sea was really clear, great for snorkelling. We were there 3 days, one of which we went to a national park inland - Krka - with lakes and waterfalls, lovely but it was really hot and quite crowded. Then we drove 4 hours north to Krk island, we didn't like the campsite there so much, our place had no shade at all so we left after 2 nights.
Then Istria, we went to a huge campsite, like a small town, but it was really great, there was a pool for kids, kid's club with activities, bars, playgrounds, restaurants and shops all over the place, I would definitely go back. Also good value, we spent about ?50 a night, food and restaurants were cheaper than here. In general everything was cheaper relative to here compared to when we went in 2003, when it was about the same.
After that we drove back to Rome, it would've been 8 hours or so had we not got stuck at the border into Slovenia for over 2 hours, as it was Saturday.
Today more excitement, it was DD's birthday and we went to Rainbow Magicland, the new theme park near Rome, it's great, we all want to go back. No queues at all as it was supposed to rain today, it was cloudy but didn't actually rain so a definite win win :-)