|Location:||northeastcentral Attica, Greece|
|Length:|| approx. 15 km, north to south|
approx. from 10 to 15 km from east to west
Pentéli or Pendeli, (Greek: Πεντέλη, ancient forms: Pentele, Pentelikon or Pentelicus, and Vrilissos or Vrilittos (Greek: Βριλησσός, Βριληττός), Mendeli in medieval times) is a tall mountain and mountain range situated northeast of Athens and southwest of Marathon. The elevation is 1,109 m. The mountain is mainly covered with forests (about 60 or 70%). The mountain can be seen in southern Athens (Attica), the Pedia plain, Parnitha, and the southern part of the northern suburbs of Athens. Houses surround the mountain, especially in Vrilissia, Penteli, Ekali and north of Gerakas.
In antiquity, Penteli was famous for its marble which was used for the construction of the Acropolis and other buildings of ancient Athens. Penteli marble is flawless white with a uniform, faint yellow tint, which makes it shine with a golden hue under sunlight. The ancient quarry is protected by law and used exclusively to obtain material for the Acropolis Restoration Project. The roadway used to transport marble blocks from the quarry to the Acropolis in antiquity is a continual downhill and follows the natural lay of the land; it has been researched and fully documented by the chief Acropolis restoration architect, Professor Manolis Korres in his award-winning book "From Pentelicon to the Parthenon".
A monastery is located in the middle of the mountain NE of city centre.
A fire in early July 1995 consumed much of the mountain forest and the eastern half became residential areas of the Athens area. The volume of smoke was tremendous; it nearly covered the entire northeastern part of Athens. All terrestrial television stations covered the fire, with the exception of some times on the weekend. The fire lasted about 5 days; it began on Friday and continued into the next week. It reached east of Penteli about 5:30 PM local time and then the Pentelis and Vrilissia, consuming a couple of houses on Friday night (about 9:00 PM EET, 7:00 PM UTC), the northern range on Saturday morning, then Rhea on Saturday afternoon, Anoixi on Monday, and Dionysus communities on Saturday. It consumed three quarters of the slopes of Penteli. It was the worst forest fire Athens and Greece had seen in the 20th century. Housing development took place in the eastern half of the mountain which removed whats left of nature from the mountain and streets are grid and circular. Lots are luxurious and later built several houses. A mining area also removed whats left from nature in the eastern half. The northern half remains heavily forested.
After the major forest fire of July 1995, three years later in the area of Drafi, mudslides blocked roads as a rock clogged off a residential road. Series of mudslides occurred several years later and devastated a few homes and continued some to this day.