Tunnel Golf

Tunnel Golf is played in a tunnel. These are the details:
The tunnel is very long and meandering.
It has wide spots, slopes, ascents, descents, curves, narrow and wide sections, but it's always a tunnel with a roof, curved sides and floor.
The tunnel has one side made completely from armoured perspex, meaning that spectators can follow the route and observe the game in total safety. The players however must wear helmets and padded clothing as they risk being struck by their opponent's golf balls as they ricochet down the tunnel.

All other aspects of the game are present ie sand pits, water traps, but there are other obstacles only really possible in a tunnel - ie pillars instead of trees; dimly illuminated sections; cross wind area; water cascading from the ceiling area to create zones of adversity.

Also, I nearly forgot to mention, Tunnel Golf doubles up as a subatomic particle accelerator! This is how the accelerator got its funding in the first place.