What was a polluted wasteland for many years has now become an oasis for holiday travelers and their children.Over 9,000 people visited Yarkon National Park on the third day of hol hamoed Passover, enjoying its blossoming foliage, floating pond lilies and sprawling lawns. At the foot of Tel Afek-Antipatris, a portion of the park located near Rosh Ha’ayin, hundreds of families were picnicking on a huge grassy knoll under the shelter of scattered trees. Some parents relaxed on straw mats while others preferred the shade of tents, but children freely kicked around soccer balls and dipped their bare feet in the Yarkon River. Up a winding, overgrown path around the side of a rain pool stood the remains of the Antipatris fortress, which was active from about 63 BCE to 324 BCE and on Tuesday had become quite active once more. Inside the cardo – the ancient market area – the Israel Nature and Parks Authority (INPA) was hosting a day filled with Olympicstyle games for families, in honor of the upcoming London Summer Olympics. Each family received a form on which game station managers recorded the family’s scores in a particular competition.One of the competitions involved building an obelisk out of giant Styrofoam cement-like blocks, as tall and as quickly as possible.Wearing construction hats, children wrapped their small arms around the blocks and handed them off to their taller parents for building. At an adjacent station, families were putting together arches out of a wooden material made to look like stone, with the aim of getting their arch to stay put for at least 20 seconds.A bowling station gave children the opportunity to knock down ceramic plates with their rolling skills, while a nearby rock toss demanded that they throw large stones as far as possible. There was a horseshoe-throwing pavilion as well, and a bulls-eye dart toss seemed to provide a challenge even for the bigger kids.Several times throughout the day, on a stage in the corner of the fortress, three families received medals for their competition victories, stepping up onto elevated steps indicating first, second and third place – a la the gold, silver and bronze steps for Olympic medal winners.In addition to games, there was a drum circle for children, in which toddlers beat sticks on the bottoms of upside-down trash cans, following the rhythm of an instructor. Under another tent was a selection of toys such as ribbon twirlers, juggling rings and pins, and devil sticks, which often ended up landing on the ground, in between a child’s – or parent’s – feet. A giant wooden chess set also stood in the sunlight, as tall as some of the children playing with the pieces.Tom Amit, manager of Yarkon National Park, told The Jerusalem Post that while huge crowds had gathered here for the Olympic games on this Passover Tuesday, the increasing popularity of the park was nothing new.Once a month, the INPA conducts an event like this one, each time drawing a crowd of about 5,000-6,000, he said. Next month, there will be a Shavuot-related event, while in the future there will be a festival of frogs, according to Amit.“We want to give people the extra value of nature,” he said. “More people come when you are doing these kinds of events.”Even during the first two days of hol hamoed Passover, when there was no special event taking place at the park, about 3,000-4,000 people came to visit and barbecue there each day, he explained. In order to keep people happy and make sure no one was waiting on intolerable lines, he had about seven ticket collectors taking money from cars at the entrance-way.Since the government began rehabilitating the once entirely polluted Yarkon River, there has been an increase not only in human visitors, but also in animals – who have come to stay, according to Amit.“There are much more animals than we saw two or three years ago,” he said, naming frogs, foxes and porcupines as particularly common inhabitants nowadays.The Yarkon bleak fish, which was once common in Israeli streams, was recently reintroduced into the Yarkon, he added.“I think it has become very beautiful in the last few years,” he said. “We’re putting in a lot of effort into making it a better place, and also, it’s in the middle of the country. There are more than three million people half an hour’s drive from here.”Of all the days of hol hamoed so far, Tuesday was the most popular among national parks and nature reserve travelers, with the INPA reporting over 300,000 people at its sites. Aside from the Yarkon National Park, which had the most visitors that day, Ein Gedi, Ashkelon and Caesarea had approximately 5,000. Tel Dan, Nahal Iyun and Nahal Amud followed with about 4,500 people, while the Banias Nature Reserve had about 4,000 visitors.Parks and forests under Keren Kayemeth LeIsrael-Jewish National Fund’s administration had about 220,000 visitors on Tuesday, with many parking lots filled to capacity, the organization said.