Southsea Railway
This line was opened in 1885. It was closed during the First World War and never re-opened.
The line went through Lidl's car park and down the back of the houses in Heidelberg Avenue. A 'back alley' on the other side of Devonshire Avenue marks its route very clearly. It then went through Pepys Close, crossing Albert Road where the Co-op is, went under the bridge carrying Old Bridge Road and along Parkstone Road to the terminus adjacent to Chewter Close.
Main Station

The picture above shows the station before the high-level extension to Portsmouth Harbour was built.
From the Main Station

Above shows the Dockyard Branch crossing by Edinburgh Road, the location of which is still marked
The line to Portsmouth Harbour then extended across the water as shown, also into the dockyards
Southsea Miniature Railway
This had its main station where the Sea-Life centre is and looped around by the bandstand.
Hilsea Miniature Railway
From the Lido to Alexandra Park. The color picture shows a remnant of the line.
Tramway

This is the former tram shelter from Guildhall Square and Cosham, now to be seen in Gunwharf Quays.
Portsdown and Horndean Light Railway
A tramway between Cosham (the current 'bus station' and Horndean, via Portsdown Hill. The route was alongside the A3 all the way.