Fruit trees (prunus) id

They aren't strictly in my garden, but they are very nearby. I was just wondering whether anyone could tell me what exactly they are? There seems to be a lot of quite similar species and I'm stumped!

This one has lots of very round yellow fruit. Most has already been foraged by my neighbours, but nobody seems to be able to tell me exactly what it is! Inside there is a small stone. The flesh is sweet and the skin is lovely and zingy.
http://i1223.photobucket.com/albums/dd517/gemini1287/TreeA.jpg
http://i1223.photobucket.com/albums/dd517/gemini1287/TreeA_fruits.jpg
http://i1223.photobucket.com/albums/dd517/gemini1287/TreeA_fruit_closeup.jpg

Initially I thought this second one had sloes on it, but there are hardly any vicious thorns, so I wasn't sure. The fruits are about 1cm long. I didn't eat any of these. Sorry the pictures aren't great, but the ones I photographed were the other side of a fence.
http://i1223.photobucket.com/albums/dd517/gemini1287/PlantB.jpg
http://i1223.photobucket.com/albums/dd517/gemini1287/PlantB1.jpg
http://i1223.photobucket.com/albums/dd517/gemini1287/PlantB_fruits.jpg

Many thanks in hope!

 

The first 3 pics look like cherry plums (which will taste sweet), also known as mirabelle or myrobalan plums, and the last 3 appear to be sloes (if you taste them you'll want to eject them from your mouth).

 

The second lot, as there are no thorns, I would say are Damsons.

 

But they are only

, too small for damsons and also the wrong shape - roundish, like sloes, not elongated like damsons.

 

Sorry, didn`t see the 1cm remark. However, if there are no thorns present, they are not Sloes, ( Prunus spinosa ).

 

See this link... there is a thorn!

http://i1223.photobucket.com/albums/dd517/gemini1287/PlantB_fruits.jpg

Therefore it is Prunus spinosa. Common name Sloe.

 

There are thorns present:

 

There are thorns, yes, but they are very occasional. So it's looking like they are probably sloes then.

Gosh, I'm glad the first tree was an easy one! Many thanks for the responses.

 

Some sloe bushes don't have many thorns, so what convinced me most was the size (1cm/10mm) as the damsons I'm picking now are approx. 25mm diameter.

The taste test is the clincher. Some damsons can be a bit sour, but an overwhelming desire to spit it out is a sure sign it's a sloe.