Coasterpedia:On this day/04 21

2018	K2, a steel roller coaster manufactured by ABC Rides, opens at Karls Erlebnis-Dorf Elstal in Wustermark, Brandenburg, Germany
2017	Sol Spin, a Ventura ride manufactured by Mondial Rides, opens at Knott's Berry Farm in Buena Park, California, USA
2011	Accelerator, a steel shuttle roller coaster manufactured by Vekoma, opens at Drayton Manor Theme Park in Drayton Bassett, Staffordshire, England, UK Plohseidon, a steel family roller coaster manufactured by Zierer, opens at Freizeitpark Plohn in Lengenfeld, Saxony, Germany
2008	Himalaya, a steel spinning family roller coaster manufactured by Fabbri, opens at Adhari Park in Khamis, Northern, Bahrain Bumper Cars, an Autoscooter ride manufactured by I.E. Park, opens at Adhari Park in Khamis, Northern, Bahrain Crazy Clown, a Hully Gully ride manufactured by Sartori, opens at Adhari Park in Khamis, Northern, Bahrain Disk'O, a Mega Disk'O ride manufactured by Zamperla, opens at Adhari Park in Khamis, Northern, Bahrain Eureka, an Interactive Eureka ride manufactured by Preston & Barbieri, opens at Adhari Park in Khamis, Northern, Bahrain Flying Carousel, a Flying Swinger ride manufactured by Preston & Barbieri, opens at Adhari Park in Khamis, Northern, Bahrain Flying Dragon, a Mini Pirate Ship ride manufactured by SBF Visa Group, opens at Adhari Park in Khamis, Northern, Bahrain Freak Flight, a Barnstormer ride manufactured by Zamperla, opens at Adhari Park in Khamis, Northern, Bahrain Japan Coast, a Tagada ride manufactured by Fabbri, opens at Adhari Park in Khamis, Northern, Bahrain Jump Around, a Jump Around ride manufactured by Zamperla, opens at Adhari Park in Khamis, Northern, Bahrain Jumpin' Star, a Jumpin' Star ride manufactured by Zamperla, opens at Adhari Park in Khamis, Northern, Bahrain Log Flume, a Flume Ride ride manufactured by SBF Visa Group, opens at Adhari Park in Khamis, Northern, Bahrain Mini Bumper Car, a Mini Bumper Car ride manufactured by Zamperla, opens at Adhari Park in Khamis, Northern, Bahrain Mini Carousel, a Merry Go Round ride manufactured by SBF Visa Group, opens at Adhari Park in Khamis, Northern, Bahrain Mini Jets, a Mini Jets ride manufactured by SBF Visa Group, opens at Adhari Park in Khamis, Northern, Bahrain Ontario Falls, a Giant Slide ride, opens at Adhari Park in Khamis, Northern, Bahrain Rockin' Tug, a Rockin' Tug ride manufactured by Zamperla, opens at Adhari Park in Khamis, Northern, Bahrain Spring Tower, a Spring Ride ride manufactured by Moser's Rides, opens at Adhari Park in Khamis, Northern, Bahrain Super Jumper, a Super Jumper ride manufactured by SBF Visa Group, opens at Adhari Park in Khamis, Northern, Bahrain Tea Cup, a Tea Cups 6 ride manufactured by SBF Visa Group, opens at Adhari Park in Khamis, Northern, Bahrain Adhari Park opens in Khamis, Northern, Bahrain
2007	Pandemonium, a steel spinning roller coaster manufactured by Gerstlauer, opens at Six Flags St. Louis in Eureka, Missouri, USA
1990	Shockwave, a steel stand-up roller coaster manufactured by Intamin, opens at Six Flags Great Adventure in Jackson, New Jersey, USA
1962	Space Whirl, a Space Whirl ride manufactured by Arrow Dynamics, opens at Century 21 Exposition in Seattle, Washington, USA