Hawaii officials have long been warning people to stay away from Sacred Falls, a dramatic waterfall where a landslide killed eight hikers more than 15 years ago.

But hikers keep returning, encouraged by gushing reviews on websites and YouTube.

Now the state is pushing back with its own online campaign.

It's releasing a video showing a law enforcement officer citing people for criminal trespassing. It features interviews with officers talking about risking their own lives to rescue people who get in trouble in the valley.

Sacred Falls is about an hour's drive from Honolulu on Oahu's lush eastern side. A park there used to be open to the public, but the state Department of Land and Natural Resources closed it in 1999.

That's the year tons of boulders, some the size of small cars, came crashing down on dozens of hikers visiting on Mother's Day.

Witnesses at first mistook the roar they heard for a flash flood. Instead, a chunk of the upper cliffs had slid down to the base of the falls where people were sitting and swimming.

More than 50 people were injured in addition to the eight killed.

The department has since posted signs warning about flash floods and rock falls at the park entrance and along the old trail. Signs note it's illegal to enter and that the fine for trespassing is $2,500. Even so, law enforcement officers issued more than 120 citations for trespassing last year.

Officers say people tell them they read about the hike online and that the warning signs are only posted to protect the state from liability.

Many reviews note the hike is illegal and warn about the fines, yet also detail the waterfall's beauty.

One review at alltrails.com described Sacred Falls as "probably the most beautiful waterfall that I have ever seen." A YouTube clip from 2013 with more than 15,000 views shows a man exclaiming "Holy cow, it's pretty" while filming the cliffs.

Amplifying the dangers is that the valley is so narrow and deep that firefighters aren't able to lower rescue baskets to the waterfall from helicopters because their ropes aren't long enough. Firefighters must hike in to help anyone out.

"What people often don't consider, is that if they get hurt and have to be rescued they are putting emergency personnel at great personal peril," Dan Quinn, the department's state parks administrator, said in a statement.

Sacred Falls is just one of several outdoor sites in Hawaii that are closed to the public but that are reviewed on social media sites. Online reviews direct hikers to climb Haiku Stairs — an Oahu trail that's also dubbed "Stairway to Heaven" — at night to avoid security guards posted there during the day.