Travelling around mysterious places of Great Britain

the past participle of the main verb
The present simple passive form is: am/is/are+ past participle
e.g. English is spoken all over the world.
The simple past passive form is: was/were+ past participle
e.g. The project was finished yesterday.
We use the passive when we want to focus on the action of the verb rather than on the person who carries out the action
e.g. The meeting was cancelled last week.
We introduced the agent with by as the preposition. The agent is mentioned only when the identity of the person is important.
e.g. Penicillin was discovered by Alexander Fleming.

the subject in the passive sentence
The active verb changes into a passive form
The subject of the active sentence becomes the agent

house is painted by the decorator.

Note: only the verbs that take an object can have passive forms.