The largest wooden inverted rollercoaster in Europe has opened today at Tayto Park in Co Meath.
The Cú Chulainn Coaster is made from 800,000 kilos of wood and travels up to 100 kilometres an hour.
The ride drops nearly 30 metres in a couple of seconds, and has a section of track that almost goes upside down.
Up to 1,000 people an hour will be able to go on it.
Its structure is made up of more than 100 tonnes of steel, and 700,000 nails and bolts.
More than 70 builders and engineers from The Gravity Group in Ohio worked on the construction of the Cú Chulainn Coaster since the summer of 2014.
These students from St Mary's School in Ashbourne were among the first to try it this morning.
The project engineer, Corey Kiepert, has been involved in creating around 25 roller coasters across the world.
So what is it like? Something like this:
