Long lost treasure in London

Question

Your guardian, Lawrence Nigel-Dalby, has passed away. He had looked after you since you were three, when your parents had died in a car crash.

You knew very little about Lawrence, he told you very little about his life. Sometimes he would disappear for weeks, apparently 'on holiday', but would come back bloodied and battered. So one evening you eavesdropped on him.

You heard him on the phone talking about the Lost treasure of London. You discovered that his 'holidays' were actually quests to find it.

You also heard about another treasure hunter who would beat up your guardian any time they crossed paths. Now that Lawrence is dead you suspect the treasure hunter murdered him. You also suspect he did this because your guardian had found the treasure.

You found a note from your guardian on the table the day he died 'on holiday':

I'm sorry I couldn't see you grow up, but that's how life is. The truth is in the next sentence that we never say or draft. No one knows where the treasure lies, but no one ever gives up. People think they're close but really they are all at sea. Remember that I love you. Think of my last words and don't heed the goodbye at all. As this is my last letter to you, keep this message in last letters.

Lawrence Nigel-Dalby

You need to work out where the treasure is before another treasure hunter comes to interrogate, and maybe also kill you.

Where is the treasure hidden?

Answer 1

The treasure is at

St. Paul's (a cathedral in London)

As deduced by

The phrase "Think of my last words" points to the final words of the letter, "last letters."
"The truth is in the next sentence" is referencing "The treasure lies"
Put those two fragments together makes the sentence "The treasure lies in last letters."
The last letters of each sentence are STPAULS, from which I got St. Paul's.

Disclaimer:

this reasoning was provided by the author. I saw the words, "last letters" and immediately jumped on them, skipping the rest of the clues. Whoops.