Obelisk

An obelisk was a pillar-like structure, that tapered towards its tip. It usually had four sides and a small pyramid-like cap on top. Many races and cultures constructed obelisks, and for a variety of purposes, such as monuments, recording devices and time travel devices. 

Obelisks of note

 * Collector obelisk
 * Hasdrubal Obelisk
 * Obelisk of Luxor
 * Preserver obelisk
 * Jelorakem