I have lived in Mumbai for a great part of my life and I pride myself on always taking an interest in its History.
But strangely I have never done the darshan of Lalbaug cha Raja. I had always felt that its fame was due to the fact that it is 'a very big Ganesh'
This time I was asked if I would accompany a friend to Lalbaug cha Raja. I read that invitation as a bulaava (call) So I did go. I am told that whatever you ask the Raja, He grants. Read on:

Lalbaug cha Raja history
The Mandal, formerly known as 'Sarvajanik Ganeshotsav Mandal, Lalbaug' was founded in the year 1928,because of a vow (Navas) for construction of the present Lalbaug Market at its existing place. The market place at Peru Chawl was shut down in 1932. Hence, the fishermen and vendors who used to sit in the open place vowed to Ganesha for permanent place for their market. With the consistent efforts and support of the then local Councillor-Late Shri. Kuwarji Jethabhai Shah, Dr. V. B. Korgaonkar, Shri. Nakhawa Kokam Mama, Bhausaheb Shinde, Dr. U. A. Rao and the local residents, the landlord Rajabai Tayyabali agreed to give a plot for construction of a market. As fulfillment of their wish, the fisherman and the traders established the Ganesh Idol on 12 September 1934. The idol was dressed in the customary fashion of fisherman. Since that day onwards, this Lord Ganesh has become popular as it fulfills the wishes of devotees. The Mandal was formed in the era when the freedom struggle was at its peak.
Due to the communal riots in 1946, orders were issued to change the route of this Ganesh Immersion Procession. But, the then office-bearers of the Mandal refused to change the route and, after 21 days, the procession was taken by the same route under the supervision of then Volunteers Pandurang alias Babu Sayle, M. S. Pawar and Dattaram Joshi. After independence, the agenda of the Mandal was modified and accordingly the Mandal decided to contribute in uplift of the Country. The Mandal donated its balance amount to the Kasturba Fund, the Mahatma Gandhi Memorial Fund in 1947 and to Bihar Flood Relief Fund in 1959. The social issues were also highlighted in the plots during Ganesh Festival.

After 1958, the number of devotees of Lalbaugcha Raja increased substantially. During this get together, eminent personalities of different fields, office bearers of various mandals and well-wishers are invited...

Visarjan Tarafa: Traditionally the Ganesh idols are immersed in water during its Visarjan. Hence in order to immerse the idol of Lalbaugcha Raja, Mandal always takes proper precautions so that the visarjan takes place in a manner the Raja deserves. Accordingly, after consulting some experts and experienced persons, Mandal has purchased a Tarafa (Iron Raft), which makes it possible to dissolve the idol of Lalbaugcha Raja in deep sea water, conveniently. The Tarafa is prepared by M/s. A.V. Engineering.In the year 2010-11 the tarafas were imported from australia
[edit]Present day

In the year 2009, the Mandal expected around 10 million people to visit This 'Great Raja'.