Anyone who has lived in Japan for some time cannot help but be struck by the large number of traditional festivals held around the country.
Many of them run to a climax with colourful processions through the streets to the sounds of ancient melodies.
A good deal of time and money obviously goes into preserving those traditions.
But none are as elaborate or as ancient as the ritual that takes place at the Ise Grand Shrine, a complex of 125 Shinto shrines in Mie prefecture in central Japan, where entire shrines are replicated once every 20 years.
This year happens to be the final year in the 20-year cycle which will see two of the shrines renewed for the 62nd time in a ceremony known in Japanese as "Shikinen Sengu".
Shikinen means a specified year, while Sengu means moving of the shrine.
The Ise Grand Shrine is the most important shrine in the Shinto religion, and to which the prime minister of the day as well as Japanese royalty make regular pilgrimages.
Tradition also dictates that the Ise Grand Shrine is watched over by a high priest or priestess who must be a member of the Japanese imperial family.
The 125 shrines that make up the Ise Grand Shrine are spread out over quite a vast area, with many of them located in and around the city of Ise.
The two most important of the shrines are the Naiku ("inner shrine") which is dedicated to Amaterasu-o-mikami, the goddess of the sun, but also of the universe and among the most important in the pantheon of Japanese deities.
According to Japanese mythology, the emperor is said to be a direct descendant of this goddess.
The other is the Geku ("outer shrine"), located 6 km away from the Naiku, which is dedicated to Toyouke no o-mikami, the deity of agriculture and industry.
At both the Naiku and the Geku, the structures that make up each shrine are rebuilt on an adjacent site once every 20 years to exacting specifications using only cypress wood and thatched roofs following architectural styles said to go back some 1,300 years.
Even the contents of the structures, from ornaments to religious treasures, are renewed as well.
The old structures are then torn down.
Each rebuilding alternates between the two sites at each of the shrines.
The Sengu ceremony for the Naiku takes place on Oct 2, while that for the Geku will take place on Oct 5, replacing structures last built in 1993.
The Sengu ceremony is shrouded in mystery and mostly cannot be viewed by people other than the participating priests themselves.
The public is also unable to view the actual structures that are being renewed.
Access to both the Naiku and Geku are greatly restricted, even normally.
Although thousands of people visit both shrines each year, they are limited to viewing the tops of the thatched roofs that cover the structures, which are completely shielded from view by tall wooden fences.
The Sengu ceremony first took place in the year 690 and has been continued to this day, except for a long break during the Warring States Period from the mid-15th century to the early 17th century.
The Sengu cycle was also delayed by World War Two by four years, resuming in 1953.
Why do the Japanese go to such great lengths to keep alive this ceremony?
One important reason stems from the Shinto belief in the impermanence of all things and that nature is constantly being renewed.
The freshness of the shrine structures therefore symbolises eternity.
The other reason is that the Sengu ceremony provides a surefire way of passing down techniques not only in traditional shrine building, but also in arts and crafts, from one generation to the next.
While many ancient cultures resorted to the use of stone for monuments that they wished to preserve for posterity, the Japanese use of wood - which is abundant in this country - mandates that they keep renewing the structures periodically.
The Sengu ceremony does not come cheap either.
The cycle that ends this year comes with a bill of some 57 billion yen (S$725 million), a 74 per cent jump over the previous cycle. The money comes largely from public donations.
Unlike before World War Two, the government does not contribute a single yen as religion was separated from the state under Japan's post-war constitution.
Some 8,500 cubic metres of cypress wood, including logs over one metre in diameter and over 400 years old, go into the construction.
The Ise Grand Shrine even maintains its own cypress forest to ensure that there will be supplies of wood 200 years hence.
Experts believe the 20-year cycle was chosen for many reasons.
Firstly, 20 years is widely regarded as one generation.
Secondly, unlike at the well-known Todaiji Temple in Nara, the largest wooden building in the world, the cypress wood used at Ise is not varnished and therefore can remain in more or less pristine condition for no more than about 20 years.
The wooden pillars used in the construction at Ise are also only sunk into holes into the ground and not reinforced with stone bases as at Todaiji for instance.
By sheer coincidence, the 62nd Sengu ceremony takes place during an important year for Japan, which has been marked by encouraging signs of economic recovery and Tokyo's winning bid to host the 2020 Olympic Games.
In the Japanese psyche, the Sengu ceremony will no doubt reinforce confidence that Japan is finally coming out of the woods.
