Aetherius Society members during a previous visit to Pen y Fan.
Groups of UFO believers will make the trip to two British hills next weekend to pray for peace and spiritual uplifting.
The members of the Aetherius Society will gather at Pen y Fan, south Wales's highest mountain and The Old Man of Coniston, once the highest point in Lancashire, for ceremonies at the sites they regard as holy mountains.
The society members are advocates of the late George King, who believed there are 17 other holy mountains throughout the world, charged with spiritual energy by extraterrestrials from Venus and Mars, and by other highly evolved spiritual intelligences.
Society spokesman David Trimble said: "Members believe that by chanting mantras and saying prayers on the mountain they can access this energy, and send out light to bring about peace, healing and much-needed spiritual upliftment in the world."
The meetings will be held next Saturday, 25 August, at the sites in the Brecon Beacons and Lake District, where followers of the society believe the hills have been charged with spiritual energy by a cosmic being known as The Full Aspect of Nixies Zero Zero Two.
Mark Bennett, an international director of the Aetherius Society, plans to take part in the pilgrimage to Pen y Fan.
Mr Trimble added: "In 2008, an Aetherius Society pilgrimage to Holdstone Down in Devon, another of the 19 mountains around the world believed by members of the society to be holy, was dedicated to the praise and appreciation of advanced extraterrestrial beings in this Solar System, who are currently helping Earth.
"In one of the most amazing so-called coincidences of UFO history, just hours afterwards there were around 200 UFO sightings all over the UK, a record number according to local and national media."
Pen y Fan, at 886m (2,907ft), is the highest point in southern Britain and is famed as a proving ground for the fitness of British special forces, who had to complete the Fan Dance, a gruelling 24km (15-mile) march traversing the peak twice.
Old Man of Coniston, one of the society's 'holy mountains'.
The Old Man of Coniston, the 803m (2,634ft) Lakeland fell, once had the distinction of being the highest point in Lancashire, a title now held by the unassuming rise of Green Hill, a 628m (2,060ft) outlier of Gragareth on the ridge rising to Great Coum in the western Dales.
The society is named after Aetherius, a being the movement's founder claims to have telepathically contacted and channelled. Aetherius is believed to be a cosmic master from Venus.