Dead pandas and Christmas trees

I am driving Eldest back from her swimming lesson, en route to pick up T'wife and Youngest for a day out in London. We are going to the British Museum, which I have some misgivings about: there are some great things to see there if you are at all interested in history, or culture, or anthropology - but none of those subjects feature highly on either of my daughters 'must see' list. However, as there are no Museums dedicated to either Bella Sara, My Little Pony or 'wiping bogies on your sister', it will have to do. For her part, my wife (whose idea this trip is) is certain it will be great, because their website says there is a 'Children's trail'. I am far less convinced, because unless this 'Children's trail' winds it's way through a display of Hello Kitty! merchandise, I can't see it holding their interest. (From personal recollection there are an awful lot of ancient clay pots in the British Museum. You can call it a 'Children's trail' all you like, but it's still clay pots in display cases, even if you give them a free colouring book...)
Nonetheless, I feel it my duty to instill some kind of anticipation for the day's forthcoming events in Eldest.
"So, are you excited?" I ask. "About going to the museum today?"
Eldest signs theatrically and gazes out of the window. "I have been to the museum before..." she says, in a voice that suggests that any discussion on so mundane a topic fills her with world-weariness..
"Not this museum, you haven't" I say.
"Yes, I have. It has a dead panda in it."
"No, that's a different museum."
"Then it is the one with the old aeroplanes."
"No, that's another different museum..."
"It is the one with the dinosaur bones?"
"No. That is the same museum as the first one. The one with the panda."
"The dead panda. The dead panda in a case..." (This is said in an accusatory tone, as if she suspects that I was somehow responsible for having the panda killed and stuffed, just so that it could be ready for our visit)
"Yes, yes - the dead panda in a case. That is the same museum as the one with the dinosaur bones. We're not going there."
"You take us to a lot of museums with dead animals in..."
"What? I don't! I've taken you to two! The Natural History Museum and the Tring Zoological museum."
"Which is the one with the dead armadillo?"
"I don't know...wait, actually, I think they both have dead armadillos."
"Which one are we going to, then?"
"We aren't - look, just let me tell you about it without asking more questions, OK?"
"I don't remember going to the Christmas Tree Museum with you..."
"What?
"The Christmas Tree Museum."
"Eh?...ah, no, I said 'history' museum. Natural History Museum. Not 'Christmas tree' museum..."
"I thought you said 'Christmas tree'..."
"Well, I didn't. Anyway, the museum we are going to see today..."
"Is it the Christmas Tree Museum?"
"No! No, it is not. There is no Museum of Christmas Trees."
"There is!"
"There isn't."
"Yes, there is! I remember now. We went once. There were lots of trees and decorations."
"You...did?" (I study her face in the rear-view mirror. It certainly looks like she is telling the truth, but then she has half my genes and I am a consummate bullshitter, so appearances can be deceptive)
"Yes," she says, with a note of finality. "We did."
"Really?"
"Really."
"When?"
"We went with Mummy. You weren't there. She bought an apple decoration for our tree."
"That...that wasn't a museum. That was a shop. More specifically, it was the Garden Centre."
"No, wait - we are both wrong!" she announces with triumph. "I remember now! It wasn't a shop or a Museum, it was a whole world. It was called Christmas World..."
"No! No, it was still the Garden Centre...look, that doesn't matter: we are not going there either. We are going to a new museum today - you haven't seen it before. It is called the British Museum."
"Has it got dead animals in it?"
"No."
"Has it got any..."
"Before you ask, no, there are no Christmas trees."
"What has it got then?"
I struggle for a second to think what to say. The British Museum contains a myriad of fabulous historical artifacts, a great many of which appear to have been stolen from other countries back when Britain had an empire, and which those countries would quite like to get back. As a result whenever I visit the place I get a strange mixed feeling, consisting of both a huge sense of awe and a twinge of shame. But these are hard concepts to get over to a five-year old, and you also don't want to oversell it: I can recall vividly my own childhood sense of disappointment when one of the 'Wonders of the World' that I had been promised turned out to be some carvings, and not the giant menacing statue I had been hoping for.
"It has a stone with three languages carved into it," I tell her. "And some statues. And quite a lot of old pots."
She contemplates this information.
"It sounds boring..." she finally announces.
"Mummy says there is a Children's trail..." I say, and then pause before adding: "This is all her idea..."