Surabaya has been an important city of harbor for centuries before Dutch arrived in Indonesia. Kalimas harbour is situated in the older part of the city, that was the main gate for trade and folks economy. Everyday traditional boats or phinisi schooners with colorful painting are there anchor for trading activities. Approximately spans 2 km, this harbor line with warehouses and wharves. As Surabaya grows into a pivotal city of Indonesia, this harbor remains its function as goods movement to and fro the harbor.

Early morning is the best time to visit this harbor as the boats are making preparation to sail to other parts of Indonesia such as Papua, Kalimantan, Sulawesi, Ambon, Bali and etc. The harbor was also functioned as transit port where ship should unload goods and then moved to smaller boats to be sailed through Kalimas River to the city of Surabaya. Now this activity can bot be seen anymore here.

Visiting the harbor will remains visitors that sailing was part of Indonesian heritage as Indonesia is the biggest archipelago country in the world. Beside seeing colorful schooners, visitors can witness how workers work hard loading and uploading manually. Even under the heat of the sun that makes their skin get dark, the drop of perspiration, still they have hopes in their eyes. The razzle-dazzle has been their friends for life-surviving.

There are remains of Dutch colonialism in Surabaya, that witness how Old Surabaya looks like. One of the remains is old bridge that was called Ophaalburg (Dutch). This bridge could be lifted up when there was boat passing through the river. The bridge is a proof that in the past there was sailing activities from Kalimas Harbor to the inner city of Surabaya through Kalimas River. And there was a harbor in the heart of the city where the boats unloading goods. In 1925, factories were established in Surabaya, as Surabaya became Industrial city.

The harbor is also a very important part of Surabaya history where Surabaya got its name. On 21 May 1293, the founder of Majapahit Empire Raden Wijaya beated Kubilai Khan at Ujung Galuh, the former name of area of Kalimas Mouth and Perak Harbor. According to legend, there was a fierce fight between a shark (Sura) and a crocodile (Baya) to get territory and tragically both of them died. The day when Raden Wijaya defeated Tar-tar is officially appointed as the anniversary of Surabaya.