VISITING LISBON - From Montijo Ferry (SE. of City, across Tarbus)

Parking is free at ferry car park, we stopped for 2 nights, parking lengthways across 2 bays in D2 parking area. Obtained permissions from terminal office prior to parking.
Note: Wildcamping POI car park is 3km east. Dominoes Pizza is on corner.
Costs
Ferry cost = 6.10euro return. Hourly on the hour, with 30 min extra departures for 6:30 to 8:30 am and pm.
All-day bus ticket 6.50euro. Get from office under the main entrance of the Station on arrival from ferry ( down elevator on the right )
An option is the Lisboa card which gives you free transport in its price of 20euro for 24hr or 34euro for 48hr. Not all museums are free but most are. the website does not explain that you can buy it at tourist information locations, one is at the main station you arrive at from ferry. Opens 9am.

Arrival is at Train, metro and bus terminals Cais de Cosa (check spelling). Tour bus also near as are Trams.
Lisbon areas, Belem, Baixa and Almafa and N. of city easily travelled by bus, metro or tour bus.

Belem is reached by bus 738, but does not go to Belem Torres, so get off at Monastery and walk 15 mins.

Almafa can be reached using bus 728, to see military or tile museums.

Use various to go north to Pompal monument at large roundabout then 746 to Gulbenkian museum.

Overall our day was 14 hrs and included 2 meals, for approx 50euro each.

Thanks for posting details

Pity you didn't have time to use your ticket to take the train to Sintra.. Fascinating place, with with regular bus tours and info from the tourist info.
It's a swine to try and park a MH. There.
Especially if there's a Cruise ship in.
We were there when the 3 Cunard Queens arrived together..
11000 passengers swamped all the attractions and facilities in the short time they were there.
Well worth doing the vintage tram tour of Central Lisboa, too.
Watch out for pick pockets around the train stations.