A conservation charity is urging visitors to “respect” one of the UK’s most beloved mountains amid growing concerns that a sharp increase in the number of walkers is causing lasting damage and too many people are trying to climb the peak without preparing properly.

The Snowdonia Society said Snowdon – Yr Wyddfa in Welsh – was being blighted by footpath erosion, littering and careless wild camping. The charity also said mountain rescue teams were having to save people who try to climb the 1,085-metre (3,560ft) peak in north Wales without the right equipment.

John Harold, the director of the Snowdonia Society, said he believed that many people came to Snowdon having been charmed by idyllic social media images of the mountain, the largest in Wales and England, but had little grasp of how to look after it or stay safe.

He said: “In order to respect something you need to have some knowledge or relationship with it. I think what we’re seeing is a high proportion of people coming who have seen attractive images on social media or elsewhere and thought, cool, I’ll have some of that. The root of the problem seems to be a mismatch between the knowledge, the skills people have and what they want to do.”

The number of people climbing Snowdon this summer is believed to have increased because so many more UK residents have opted to holiday in Britain.

There have sometimes been 45-minute queues to cover the last few metres to the summit and the Llanberis mountain rescue team said it had had to deal with up to six callouts a day and reported an increase in the number of people sustaining leg injuries on the mountain.

Harold said: “The simple fact is that Snowdon is a really big mountain. It is not a walk in the park, a trip down the high street or a day at a festival. People need to be better prepared and have realistic expectations about what they are going to experience.”

The Snowdonia national park authority has introduced measures to try to manage the increase in visitor numbers, including a booking system for a key car park and introducing shuttle buses. It has made the point that the national park covers 800 sq miles (208,000 hectares) and suggested people visited the beaches, the castles and the Celtic rainforest as well as making a beeline for Snowdon.

Harold said: “Access to wonderful places like Snowdon has become important to people but the pressures that come with the increased interest are significant. I would suggest that people need to ask themselves a series of questions – have I got the fitness, have I got the knowledge and have I got the equipment. It’s not enough to have a mobile phone to think that will help you out. That’s worse than useless when there’s no signal on the mountain.”

Harold said a particular social media image he believed was attracting people to the mountain was “that idyllic picture of a lonely tent on a mountain ridge with not a soul in sight”. He added: “There are people who know how to wild camp. Nobody sees them. They pitch after dark and take their tent down before the sun comes up and don’t leave a trace.

“Those sort of people are as appalled as we are by what’s being done in the name of wild camping. I’ve seen scorch marks from barbecues all over the place, broken tents scattered around.”

Harold said two-thirds of his charity’s work this year was focused on dealing with the impact of visitor numbers. “It means that other work such as managing peatland and woodland, improving access has been cut back.”

He said if people prepared properly, the mountain and organisations involved in managing it would benefit. “But it’s also much better for visitors,” he said. “It’s not fun going up a 3,500ft mountain in footwear that hurts, no fun if you haven’t got food and drink, no fun at all if you get lost. We want people to enjoy their time in Snowdonia but good preparation and a bit more knowledge means that everyone will have a better time.”