"Special Delivery" puzzle: Find the place in the U.S. where mail is still delivered by mule, using symbol substitution.

- Step 1: Understand the Cipher
The image provides a substitution cipher. Each letter of the alphabet (A-Y) is paired with a unique symbol. The goal is to decode the message by replacing each symbol with its corresponding letter.

- Step 2: Decode the First Line
The first line of symbols is:
`£ ← ∩ ← × ∩ ← £`
Using the key:
- `£` = A
- `←` = B
- `∩` = D
- `×` = S
Decoding gives: A B D B S D B A

- Step 3: Decode the Second Line
The second line is:
`∩ 5 £ ← ^ ↑ £`
Using the key:
- `5` = F
- `^` = T
- `↑` = H
Decoding gives: D F A B T H A

- Step 4: Decode the Third Line
The third line is:
`← ^ ^ £ ↑`
Using the key:
Decoding gives: B T T A H

- Step 5: Decode the Fourth Line
The fourth line is:
`→ 5 ^ ^ 5 ∩`
Using the key:
- `→` = C
Decoding gives: C F T T F D

- Step 6: Decode the Fifth Line
The fifth line is:
`5 5¬ ^ £ ↑`
Using the key:
- `5¬` = G
Decoding gives: F G T A H

- Step 7: Decode the Sixth Line
The sixth line is:
`↓ ¬ ← ∩ £`
Using the key:
- `↓` = E
- `¬` = I
Decoding gives: E I B D A

- Step 8: Decode the Seventh Line
The seventh line is:
`← ← ∩ 8 5 ∩ !`
Using the key:
- `8` = K
Decoding gives: B B D K F D !

- Step 9: Assemble the Full Message
Putting all decoded lines together:
A B D B S D B A D F A B T H A B T T A H C F T T F D F G T A H E I B D A B B D K F D !

- Step 10: Interpret the Message
Reading the decoded letters as words, we get:
"ABDBSDAB DFABTHA BT TA H CFTTFD FG TA H EIBDA BBDKFD!"
This doesn't make sense as-is. Let's look at the symbols again and try to group them into meaningful words based on common phrases or the context of the riddle ("mail delivered by mule").

Looking more carefully at the symbols and their positions, it appears the intended decoding might be:
- First word: `£ ← ∩ ← × ∩ ← £` → A B D B S D B A → "ABDBSDAB" — perhaps "ALASKA"?
Wait, let's re-examine the key. Maybe there's a mistake in reading the symbols.

Actually, looking at the symbols again:
- The first symbol `£` is A.
- The second symbol `←` is B.
- The third symbol `∩` is D.
But perhaps the symbols are meant to be read as letters that form actual words.

Let me try a different approach: maybe the symbols correspond to letters that spell out a place name.

Re-decoding with care:
Line 1: `£ ← ∩ ← × ∩ ← £` → A B D B S D B A → not meaningful.

Wait, perhaps the symbols are not single letters but represent something else? No, the key is clear: each symbol maps to one letter.

Another idea: maybe the decoded letters need to be read as a phrase. Let's write them out:

A B D B S D B A
D F A B T H A
B T
T A H
C F T T F D
F G
T A H
E I B D A
B B D K F D !

That still doesn't make sense. Perhaps I misread the symbols.

Let me check the key again:
A = £
B = ←
C = 5¬ (but 5¬ is used in the text, so maybe 5¬ is one symbol for C? No, the key shows C = 5¬, but in the text, 5¬ appears as two separate symbols? No, in the key, C is paired with a symbol that looks like '5' with a bar, which is different from '5'.

Actually, looking closely, the key has:
C = a symbol that looks like '5' with a horizontal bar through it.
In the text, we have '5' and '5¬', so '5' is F, and '5¬' is C.

So in line 5: `5 5¬` → F C

Then line 5: `5 5¬ ^ £ ↑` → F C T A H → "FC TAH"

Still not making sense.

Perhaps the answer is "ALASKA" because it's known for mail delivery by mule in some remote areas.

Let me try to see if the symbols can be mapped to "ALASKA".

A = £
L = ∩ (from key, L = ∩)
A = £
S = ×
K = 8
A = £

So "ALASKA" would be: £ ∩ £ × 8 £

But the first line is: £ ← ∩ ← × ∩ ← £ — which is A B D B S D B A.

Not matching.

Another thought: maybe the decoded message is "THE MAIL IS DELIVERED BY MULE IN ALASKA" or something similar.

Let's try to decode the entire thing again, very carefully.

First line: symbols are `£`, `←`, `∩`, `←`, `×`, `∩`, `←`, `£`
Letters: A, B, D, B, S, D, B, A → "ABDBSDAB"

Second line: `∩`, `5`, `£`, `←`, `^`, `↑`, `£` → D, F, A, B, T, H, A → "DFABTHA"

Third line: `←`, `^`, space, `^`, `£`, `↑` → B, T, space, T, A, H → "BT TAH"

Fourth line: `→`, `5`, `^`, `^`, `5`, `∩` → C, F, T, T, F, D → "CFTTFD"

Fifth line: `5`, `5¬`, space, `^`, `£`, `↑` → F, C, space, T, A, H → "FC TAH"

Sixth line: `↓`, `¬`, `←`, `∩`, `£` → E, I, B, D, A → "EIBDA"

Seventh line: `←`, `←`, `∩`, `8`, `5`, `∩`, `!` → B, B, D, K, F, D, ! → "BBDKFD!"

This is not yielding a readable message. Perhaps there's an error in the key interpretation.

Wait, let's look at the key again. The key shows:
A = £
B = ←
C = 5¬ (a symbol that looks like '5' with a bar)
D = ∩
E = ↓
F = 5
G = 5¬ (same as C? No, in the key, C and G are different. Let me check:

In the key:
C = a symbol that is '5' with a horizontal bar
G = a symbol that is '5' with a vertical bar? No, looking closely, the key has:
C = a symbol resembling '5' with a bar through it (let's call it C-symbol)
G = a symbol that is '5' with a different modification? Actually, in the key, G is paired with a symbol that looks like '5' with a bar, but it's different from C's symbol.

This is confusing. Perhaps the symbols are meant to be read as letters that form "ALASKA".

Given the riddle: "Where is the only place in the U.S. where mail is still delivered by mule?" — the answer is likely "Alaska".

And the decoded message should spell "ALASKA" or something related.

Let me try to see if the first few symbols can be "A L A S K A".

A = £
L = ∩ (from key, L = ∩)
A = £
S = ×
K = 8
A = £

So the sequence for "ALASKA" would be: £ ∩ £ × 8 £

But the first line starts with £ ← ∩ ← × ∩ ← £ — which is not matching.

Perhaps the message is "IN ALASKA" or "ALASKA ONLY".

Another idea: maybe the decoded letters are to be read as a sentence, and "ABDBSDAB" is "ALASKA" if we consider that B is L? But no, the key is fixed.

Perhaps there's a mistake in the symbol recognition. Let's assume that the first symbol is A, second is L, etc.

But the key is given, so we must use it.

Let's try to decode the last part: "B B D K F D !" — that could be "BB DK FD!" — not meaningful.

Perhaps the answer is "ALASKA", and the cipher is designed to spell that.

Given the context, the only place in the U.S. where mail is still delivered by mule is Alaska.

So, despite the decoding not yielding a perfect match, the intended answer is likely Alaska.

But to be precise, let's try one more time with the symbols.

Looking at the first line: `£ ← ∩ ← × ∩ ← £`

If we map:
£ = A
← = B
∩ = D
× = S

So A B D B S D B A

Perhaps it's "A B D B S D B A" and we need to see it as "ALASKA" by considering that B is L? But that's not correct per the key.

Maybe the key is misread. Let's list the key clearly:

A = £
B = ←
C = 5¬ (symbol with '5' and bar)
D = ∩
E = ↓
F = 5
G = ? (in key, G is paired with a symbol that looks like '5' with a bar, but it's different from C's symbol? Actually, in the key, C and G are both shown with symbols that resemble '5' with bars, but they are distinct. Let's assume C = 5¬ and G = another symbol.

In the text, we have '5' which is F, and '5¬' which is C.

So in line 5: `5 5¬` = F C

Then the message is "DFABTHA" for line 2, which might be "DELIVER" or something.

Perhaps the decoded message is "THE MAIL IS DELIVERED BY MULE IN ALASKA" but it's not matching.

Given the time, and the fact that the riddle is well-known, the answer is Alaska.

So, the solution is:

- The only place in the U.S. where mail is still delivered by mule is Alaska.
- The cipher decodes to a message that should confirm this, but due to potential symbol misinterpretation, the direct decoding is unclear. However, based on general knowledge, the answer is Alaska.