It was said in the 19th century a family squatted in the surviving chambered tomb on the right! The monuments form part of an unusual tradition on Anglesey of 'long graves' comprising of several megalithic chambered tombs in sequence. This is but one site, and includes others such as Din Dryfol, Trefignath, Hendrefor and Plas Newydd.

Edit: well that's annoying, the image didn't attach to the OP! I've added it as a comment below, apologies!

Edit x2: It works now, odd!

The Rudston Monolith is the largest single standing stone in the U.K., standing at almost 8m tall above ground. Experiencing it was a lovely end to my little adventure exploring the NE of England 🥰

Came across this lone stone at Waun Mawn. It just stands there with the hills in the background, feels like a scene from a movie.

Dating back to the Neolithic period (approximately 4500–2000 BCE), it ranks as the third-largest megalithic site in the Morbihan region and is part of the broader, world-renowned Carnac stones network.

Talatí de Dalt's quirky Taula is a standout on Menorca due to that pillar leaning into it on the left. Some say this was just a accident with a pillar falling over, but others (myself included) think it looks too perfectly-placed to have no deeper meaning.

I hope I've correctly identified this one. I took the photo well over a decade ago.

This is the tallest of Menorca's many Taula, with the upright standing 4.3 metres tall while the capstone adds another 0.7 metres of thickness to its 3.7 metres of length. It sits in the Talayotic settlement of Torralba d'en Salort and is believed to date back to c. 500 BCE.

Neolithic carvings on the Langdale Boulders, a Scheduled Monument.
There are two boulders which display prehistoric art, the westernmost displays a range of motifs including a concentric circle of 11 rings, the largest number of concentric rings known from a prehistoric rock carving site in Britain.
Dating from between 2800 and 500 BC, the boulders were in situ when carved

Kit's Coty (near Aylesford, Kent)

Built nearly 6000 years ago at the beginning of the Neolithic period, the dolmen, constructed of local sarsen stones, once stood at the end of an irregular-shaped 84m long mound bordered by shallow ditches, and was probably used for burials.

Photo taken by myself while hiking the Beara and Kerry way.

A moody shot of Castlerigg in the Lake District.

Saw this dolmen on a hike near Navarredonda de Gredos, in the region of Castile and León in Spain. It stands at the source of the river Río Tormes. Google Maps Location HERE.

Online I can only find sites such as this, that mention the standing stones as part of a hiking trail, but do not give any information about it whatsoever. Does anybody know any websites with information on spanish megalitishs?

While technically not a megalith, the Neolithic rock shelter and art on Chatton Moor deserves to be seen. Hope that's okay.