Today, the Okido at Takanawa, and a similar gate at Yotsuya, are little more than official boundary markers. However, when they were first built, these massive gates formed the first line in the military defenses that the Shoguns built to protect their capital. The Takanawa district also marks the start of the shitamachi, or "downtown" area of Edo, characterized by its tightly packed "row houses", stores, workshops and official buildings. Traditionally, the Okido is also the place where relatives and friends say their farewells to people travelling west from Edo.
The great gate and stone wall were originally built as defences to protect the city from attack. No one has ever attempted to attack Edo, and probably no one would ever dream of doing so today. In the late 1700s, Japan has enjoyed a period of peace and stability for well over 150 years! However, when Tokugawa Ieyasu, the first Shogun, began building his capital city here in 1590, the country was still in the final phases of a long era of almost continuous warfare, and Ieyasu spared no expense to build strong fortifications for his city.
The long period of civil war and internal strife was called the Sengoku Jidai (The age of warring states). It was an age of countless battles and skirmishes between powerful daimyo, and it lasted for more than a century. During this period, no part of the country could consider itself totally safe from attack, so all of the major daimyo built huge fortresses to protect their domains. Although Edo has now grown into a sprawling, peaceful metropolis, you can still see the remains of when it was a fortress city, controlled by the most powerful warlord in Japan. Massive ramparts, moats, and towering fortress walls can be seen almost everywhere you go in the city
Just outside the gate, in a wide and busy square, are many chaya (tea houses). The people of Edo eat many of their meals at tea shops or other "restaurants", rather than at home. This is partly because their houses tend to be quite small and cooking space is at a premium. Besides, it is almost as expensive to eat at home as it is to eat out, and it is definitely more work to cook. In the warm and humid climate that characterizes Edo for most of the year, food spoils quickly. Apart from pickled vegetables or dried basic foods like rice and noodles, it is difficult to store food items at home. Therefore, even when they make a home-cooked meal Edo citizens have to buy most of their food on the same day they eat it.
Because it is so difficult and time-consuming to eat at home, people in Edo (especially those from the middle and upper classes) have developed the habit of "eating out" often. Nearly every district of the city has clusters of chaya. Small restaurants and food stalls can be found on most main streets. There is a wide variety of diferent types of chaya in Edo. Some serve only tea, and often treat customers to a simplified version of the traditional Japanese tea ceremony. Others are more like restaurants, serving all sorts of food and snacks. Some chaya offer entertainment, such as singers, comedians or even amateur sumo wrestling.
The tea houses in the Okido district are all quite busy throughout the day, but interesting enough, the biggest crowds can be seen in the early morning. This is because large groups of people come to Takanawa to see off relatives or friends who are preparing to embark on journeys along the Tokaido. Takanawa Okido has traditionally been the spot where people say their farewells. In order to get a good start on the journey, most travellers leave early in the morning. That is why the shops and restaurants around the Okido are quite busy in the morning
Highway travel is extremely common in Edo Japan, perhaps more so than in any other nation of the world during the same period. The strong tradition of religions pilgrimages accounts for many of the travelers. In addition, merchants and entertainers are a common sight on the highways. However, the majority of the traffic up and down Japan's major roads is the result of the system of Sankin-kotai (alternate attendance) -- a custom that forces all of the major daimyo to spend at least four months out of every year living in Edo.
The first Shoguns instituted the custom of Sankin-kotai in order to keep an eye on their main military rivals. Japan was just emerging from the Sengoku Jidai, and the leaders were never sure how much they could trust their vassals. Tokugawa Ieyasu passed a law which forced major daimyo to build homes in Edo and to spend a part of every year living in Edo. This gives the Shogun a chance to keep an eye on them, and test their loyalty. For the other eight months of the year, they are allowed to go back to their homes in the provinces to look after their land and take care of local business. However, their wives and their eldest sons have to remain in Edo whenever they return home. If any daimyo decided to rebel against the Shogun, their wives and children could be used as hostages.
Thus, every daimyo in Japan makes an elaborate journey twice a year (one trip going to Edo and another going back to their home province). During the journey, the daimyo is accompanied by dozens, if not hundreds of assistants, retainers and family members. There is also a steady stream of lesser officials, who also travel with fairly large groups of servants and guards. These officials and advisors carry messages and information to and from the daimyo, allowing them to govern their provinces effectively even while they are in Edo.