When Historic Scotland embarked on a project to create a new visitor reception area at Edinburgh Castle last September, few could have predicted that it would unearth so much hidden history.

With any project of this scale, it is customary to involve archaeologists from the outset and this procedure turned out to be vital at Edinburgh Castle as in February 2007, just four months after work on the project commenced, construction workers came across what was later found to be part of the 17th century frontal defences, deep beneath the entrance to the Castle.

This week, as the next phase of work on the visitor reception project is completed (involving the construction of a new parapet), archaeologists are elated to have received the results of borehole samples from the area which reveal deposits dating as far back as prehistoric times.

Peter Yeoman, Senior Archaeologist at Historic Scotland said: "The results from the archaeological boring were really surprising as this technique rarely produces detailed dating evidence. The data is truly invaluable as it adds another piece to the lost history of Edinburgh Castle.

We can now be certain that the front of the castle was encircled by a pair of massive ditches dating as far back as the Iron Age, 2000 years ago. Each ditch was about 12 metres wide and 6 metres deep. Within these now infilled ditches are layers and layers of fascinating historical remains, the lower containing pottery from the 12th-13th centuries, the upper layers from the 16th-17th centuries."

Archaeological boring involves a special drilling rig which cuts a core deep down through buried archaeology. This core was recovered in a plastic sleeve and taken to Headland Archaeology Ltd’s labs in Edinburgh for analysis. Their environmental archaeologist was able to tell how the ditch became gradually infilled, and recovered dateable pottery as well as food debris from the stratified ditch samples.

Historic Scotland is investing £2.7million improving the visitor reception facilities at Edinburgh Castle, including a new website for the Castle where visitors can buy tickets online, a new modern ticket office, and a terrace/gathering area offering spectacular views over the city. It is hoped the developments will cut queue times considerably for the 1.2 million visitors the Castle welcomes every year.

Scaffolding will be taken down this week to reveal the wall which has been heightened (with new stone that matches the original) to form a new parapet facing the esplanade. Work will continue over the coming months on the north wall and the construction of the new ticket office on the terrace.

Chris Watkins, Head of Major Projects at Historic Scotland said: "It is always very exciting when a project such as this leads to the discovery of more information on the history of Edinburgh Castle. Most of the underground work on the project, including the 26m deep piles to support the new terrace, is now complete and we are progressing with the building of new stonework and the development of the website."

• Edinburgh Castle is open 7 days a week from 9.30am - 6.00pm (Apr-Sept). Admission: Adult £11.00, Child £5.50, Concession £9.00.
  
  
• A majestic landmark which dominates the capital city's skyline just as it has dominated Scotland's long and colourful history Edinburgh Castle is the best known and most visited of our historic buildings. Perched on an extinct volcano and offering stunning views, this instantly recognisable fortress is a powerful national symbol, and part of Edinburgh's World Heritage site. More on Edinburgh Castle's historic timeline (Word doc)
  
  
• Historic Scotland is investing £2.7 million in the Edinburgh Castle Visitor Reception Project with an aim to cut queues and give visitors a warmer welcome when they arrive at Edinburgh Castle. The project will halve the time taken to queue for tickets and transform the visitors’ view of the castle by removing the current ticket office from the esplanade. The project includes:
  • a new terrace and gathering area offering spectacular city views
  • a new ticket office on the terrace
  • online booking and information on events via a new Edinburgh Castle website
  • a sophisticated and swift new onsite electronic ticketing system.