Güell Park in Barcelona has an entrance fee! Although it caught me by surprise last week, the charge has been in effect since 2013, in order to limit the number of visitors to 800 per day. The gate attendant told us that this measure was taken to prevent damage to the artwork in what is now called the Monument section of the park which is a UNESCO World Heritage Site. The vast majority of the park is still free.
I began, not without nostalgia, to think about the places around the world I had visited as a child in the 1950’s – places like the Acropolis in Athens, Persepolis in Iran, the Palace of Minos in Crete—where my little brother and I were able to walk around and explore and climb as children do. We even walked into the Lascaux Caves back in 1959 when they were actually fitted with lights and ventilation for tourists, but before 1963 when public access to these colorful Paleolithic paintings was replaced with a replica cave in order to protect the paintings from being destroyed due to the mold and moisture unwittingly brought in by thousands of curious visitors.
Nostalgia for those distant memories has been replaced with gratitude and regret: Gratitude that these monuments to human creativity are still here for all of us to marvel at and regret that we were so unaware way back then of the threat we posed to such irreplaceable pieces of history. Fortunately UNESCO started designating sites for protection in 1979. When I got home I looked up the list of UNESCO World Heritage Sites and found that we had seen several in the past week: The Alhambra in Granada, the Alcazar in Seville, and some of the works of Antonio Gaudi, including Güell Park, Casa Batllo, and Gaudi’s work on the still-unfinished church Sagrada Familia. Spain, the third most-visited tourist destination, has 46 World Heritage Sites. We are far beyond the 1950’s now and tourism has increased immensely all over the world. (See the World Tourism Organization at http://www2.unwto.org/).
The Acropolis, Persepolis, and the Lascaux Caves are now World Heritage Sites, while the Palace of Minos is on a tentative list. It is well worth a look at the UNESCO web site to see a description of the ten World Heritage Site criteria and a list of official sites. You can even click on each site and read the documentation of how it meets the evaluation criteria. Go to http://whc.unesco.org/ for a look at the list. Sites are not only unique examples of human history and culture, but also include irreplaceable environments around the world, for example the Tropical Rainforest Heritage of Sumatra in Indonesia and Yellowstone National Park in the United States. There are now 832 cultural sites and 206 natural ones.
Gaudi’s works are considered “truly universal in view of the diverse cultural sources that inspired them,” including the neo-Islamic movement of the late 19th century, along with classic, Gothic, and Renaissance styles. His park was started as a unique garden-city development, only partially completed, which was incorporated into a city park with grottos and colorful ceramic mosaic sculptures including a popular dragon. People love to take their picture with that dragon, which is probably why it was removed for repair when we were there. But I am happy that it will be in place for our children and grandchildren to see.
History's Edge 
I just visited Park Güell for the first time although I been to Spain many, many times. It was delightful and unique and was undergoing some major restoration in the monument section in April 2018. We should all be grateful for UNESCO and this designation.
I remember when I able to climb up into Khufu’s pyramid in Giza in 1996!