Once the bastion of Ozzfests and 93X weekend bashes, the revamped Somerset Amphitheater will return to its metal roots Aug. 18 when it hosts one of two installments of Knotfest – a first-ever all-day lineup headed by Slipknot. Iowa's masked metal avengers will be joined by the Deftones, Lamb of God, Dethklok, Serj Tankian (A System of a Down's lead singer), Cannibal Corpse, Prong, Dillinger Escape Plan, the Urge, Gojira and more at the event, which will also be staged Aug. 17 in Council Bluffs, Iowa, at the Mid-America Motorplex.

This will be Slipknot's first show up our way since the passing of bassist Paul Gray in 2010, but it won't be their first time in Somerset: They played the same site for the 93X Fest in 2000 and Ozzfest in 2001 (the one with Black Sabbath!), plus various members have also performed there on the side with Stone Sour and Korn.

Tickets will go on sale Friday at 10 a.m. for $35 (plus $9 fees) via www.LiveNation.com. VIP packages are also being sold. As at any Somerset Amphitheater event nowadays, concertgoers can also take advantage of the newly expanded and refurbished adjoining campgrounds. In addition to the band's performances, organizers are promising (per the press release): "circus big-top tents, pillars of fire, and amusement park rides--including the legendary Ring of Fire carnival ride." Sounds like a lot of singed eyebrows and puke-covered shoes will also be part of the fun.

More details at www.knotfest.com.