Sixteen-year-old struck by lightning at Blue Mountains landmark near Sydney

An afternoon hike near an Australian landmark has taken a terrifying turn for a teenage boy struck by lightning in the Blue Mountains.

Lightning (file picture). Source: 1 NEWS

The 16-year-old was hit while on the Giant Stairway Walking Track next to the Three Sisters this afternoon as storms lashed large swathes of the state.

The teenager was treated for burns to his torso and lightning strike entry and exit wounds to his arms and feet.

Another 24-year-old man was also treated with both taken to the Nepean Hospital in a stable condition.

"This is an extraordinary circumstance, being struck by lightning is a terrifying experience," NSW Ambulance Inspector Greg Marshall said in a statement.

"Considering the circumstances, it was incredibly lucky that they were both in stable conditions when taken to hospital."

Two other people have been struck by lightning in NSW this year, at Arcadia and Dee Why on January 6.

Insp Marshall says prompt first aid is the key to surviving a strike.

"How you react to being hit by lightning depends on the circumstances and where you have been hit - most people, however, will go into cardiac arrest so those first moments of CPR are vital," he said.