I used to have a horse and my uncle had a handful of horses I got to ride as well. (My horse was stabled with my uncle's horses).
My horse was a lovely Icelandic horse/pony (they're traditionally called horses but really they're actually ponies to be honest) called Baldur. I lived in Iceland then and the only breed of horses there is the Icelandic horse (it's been forbidden to import horses into Iceland since around year 1000) as a consequence the only horse I know how to ride is the Icelandics. They have 5 gaits and are absolutely lovely.
I have a few photos from a horse trek I did back in 2000 or 2001 (I don't quite remember). I borrowed two of my uncle's horses and took my horse as well for a proper horse trek. You needed atleast 3 horses per person to be able to take part. It was a weeklong trip and SO much fun.
The horses were used to cross glacial rivers in the past so here's one of the guides showing us how it's done in a lake.
We actually got slightly lost on top of a mountain. We knew where to go and could see it but the route there was a bit tricky to find. We ended up stopping to let the guide get his head together.
A well deserved break on the longest day which was a full 8 hours of riding
and finally a picture of the herd. I was really lucky and my horse is the brown one with the yellow halter on, very easily visible there.
How you travel when you do treks like this is since the horse to people ratio is atleast 3 to 1. You turn the extra horses loose and drive them along with you in a herd. The horses have to learn how to do this properly so you often take a few young horses with you just to run in the herd without being ridden so they'll get used to the whole thing. There are people riding in the front and then people riding in the back of the herd to make sure everyone goes where they're supposed to. It's a lot of fun and the landscape can be absolutely amazing.
I miss my horse
I ended up selling him when it was clear I was going to be moving to Scotland. My uncle still keeps horses so I usually get to ride when I go home for a visit if his horses are stabled. (In iceland you pull the shoes off the horses and let them go wild for around 3-4 months in the autumn and they're not ridden at all then).