The 300-tonne, 98ft (30m) horse head sculptures were created by artist Andy Scott and sit in Helix Park, Falkirk, close to the M9 motorway.
Construction work to erect the sculptures began last year and from today members of public are allowed to get close to the structures and even inside them.
Falkirk Community Trust will take people on guided tours of the £5 million artworks, which are the centrepiece of the Helix redevelopment.
The ten guided tours running today have all sold out.
It is hoped that 350,000 visitors will visit the area each year, bringing £1.5 million of extra tourism revenue.
Glasgow artist Scott took inspiration from Scotland's history of working horses which once pulled barges along the nearby Forth and Clyde Canal when he designed the steel structures.
A new extension linking the canal to the North Sea is expected to open up the inland waterways to more boating traffic in central Scotland.
Scott is also responsible for the Heavy Horse, which overlooks the M8 at Glasgow Business Park, and the Arria statue, which can be seen from the A80 and has been dubbed ''the Angel of the Nauld''.
When construction work finished on the Kelpies, Scott said: ''It is almost eight years since I did the first sketches on the kitchen table of my then girlfriend, now wife, in Amsterdam. So to see them completed is both humbling and fantastic.
''I have always been fascinated with horses and the heavy horse was at one time the driving force in industry until after the industrial revolution.''
Tours of The Kelpies include the opportunity to get inside the sculptures.
The structures have attracted international attention, with two 15ft scale models of the horses displayed in New York along with a time-lapse video of the construction.
A light show last week helped unveil the finished work. The sculptures were brought to life with a pyrotechnic display involving fire and music.