Bulgaria is great for actually exploring some unusual areas , there’s a great resort called Albena which is very green and pretty , there is so many places you can travel too and explore and the most popular day trips are :
Cape Kaliakra
The Botanical Garden in Balchik
“Baltata” Nature Park with the river flowing directly into the sea.
Eco-park “Geranea
Nessebar which is a UNESCO heritage site - my mum and dad stayed in this resort last month and said it was beautiful!
Aladzha Monastery
Varna City Tour
There is also a jeep safari and you can get boat hire trips from there too.
Bulgaria is a great option for securing a very reasonably priced holiday with the option to add on lots of great excursions if you want them. There are some shorter holidays from some UK airports too so you don’t have to do the typical 7 nights.
I’m a travel agent (not selling or promoting) but I’ve noticed when I’ve been pricing it for customers that there was some different durations available depending on your airports x