The casing of a half-tonne bomb dating back to the second world war and a giant seascape-themed wall were on Thursday revealed among the features of the East Rail Line's new Exhibition Centre Station.

MTR architects said that to reflect the station's proximity to Victoria Harbour, a local artist has created a themed-wall named "Water Memory", complete with 1,200 photos capturing waves off Wan Chai Pier at different times of the day and year.

"The wall faces Victoria Harbour. I guess many passengers may not be able to tell east, south, west and north when they are down at the station. But if you see this wall, you will know you are facing north," said the MTR's acting chief architectural manager, Cheng Kwok-wai.

Cheng added that the walls on the two platforms feature the history of the East Rail Line as well as the challenges engineers faced during its construction.

The 454-kilogramme bomb casing can be found on the platform for trains heading to Lo Wu. Officials said it is one of three second world war bombs discovered in 2018 during the station's construction.

They also said engineers had reserved space in the station for future expansion.

The cross-harbour section of the East Rail Line is expected to open on May 15.