diff --git a/12/HotSprings.Tests/GlobalUsings.cs b/12/HotSprings.Tests/GlobalUsings.cs
new file mode 100644
index 0000000..7fef4b0
--- /dev/null
+++ b/12/HotSprings.Tests/GlobalUsings.cs
@@ -0,0 +1,2 @@
+global using Xunit;
+global using FluentAssertions;
\ No newline at end of file
diff --git a/12/HotSprings.Tests/HotSprings.Tests.csproj b/12/HotSprings.Tests/HotSprings.Tests.csproj
new file mode 100644
index 0000000..05c2d07
--- /dev/null
+++ b/12/HotSprings.Tests/HotSprings.Tests.csproj
@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.12.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0" />
+    <PackageReference Include="xunit" Version="2.4.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="6.0.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\HotSprings\HotSprings.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/12/HotSprings.Tests/UnitTest1.cs b/12/HotSprings.Tests/UnitTest1.cs
new file mode 100644
index 0000000..60c68a0
--- /dev/null
+++ b/12/HotSprings.Tests/UnitTest1.cs
@@ -0,0 +1,10 @@
+namespace HotSprings.Tests;
+
+public class UnitTest1
+{
+    [Fact]
+    public void Test1()
+    {
+
+    }
+}
\ No newline at end of file
diff --git a/12/HotSprings/HotSprings.csproj b/12/HotSprings/HotSprings.csproj
new file mode 100644
index 0000000..2150e37
--- /dev/null
+++ b/12/HotSprings/HotSprings.csproj
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
diff --git a/12/HotSprings/Program.cs b/12/HotSprings/Program.cs
new file mode 100644
index 0000000..3751555
--- /dev/null
+++ b/12/HotSprings/Program.cs
@@ -0,0 +1,2 @@
+// See https://aka.ms/new-console-template for more information
+Console.WriteLine("Hello, World!");
diff --git a/AdventOfCode2023.sln b/AdventOfCode2023.sln
index 34aded4..741151e 100644
--- a/AdventOfCode2023.sln
+++ b/AdventOfCode2023.sln
@@ -69,6 +69,12 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CosmicExpansion", "11\Cosmi
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CosmicExpansion.Tests", "11\CosmicExpansion.Tests\CosmicExpansion.Tests.csproj", "{0D6CD658-65BB-47DC-A865-E3428EBE3075}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "12", "12", "{ABF03698-B81C-45DE-B76A-C7FBC0C72DB6}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotSprings", "12\HotSprings\HotSprings.csproj", "{DB4A8A1F-54A8-4534-AE0A-027B365AA73B}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotSprings.Tests", "12\HotSprings.Tests\HotSprings.Tests.csproj", "{2731DE56-AF4B-4009-8259-2EA5A9A102FE}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -166,6 +172,14 @@ Global
 		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{0D6CD658-65BB-47DC-A865-E3428EBE3075}.Release|Any CPU.Build.0 = Release|Any CPU
+		{DB4A8A1F-54A8-4534-AE0A-027B365AA73B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{DB4A8A1F-54A8-4534-AE0A-027B365AA73B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{DB4A8A1F-54A8-4534-AE0A-027B365AA73B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{DB4A8A1F-54A8-4534-AE0A-027B365AA73B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{2731DE56-AF4B-4009-8259-2EA5A9A102FE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2731DE56-AF4B-4009-8259-2EA5A9A102FE}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2731DE56-AF4B-4009-8259-2EA5A9A102FE}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2731DE56-AF4B-4009-8259-2EA5A9A102FE}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{3F8EAC09-4BC7-43AA-B72B-48DDD2710F6D} = {8C29858C-623A-461A-BF0B-254E151CD9C2}
@@ -190,5 +204,7 @@ Global
 		{B1DA407F-DA29-4BDA-B10E-8B9A976B0C5E} = {9703A36A-A019-4ADC-93A7-9DF4EFBCBFBC}
 		{580A3C98-7A39-4323-839A-5C2E0B6E8E74} = {01A6D73F-996E-48B3-B111-2725016A49C2}
 		{0D6CD658-65BB-47DC-A865-E3428EBE3075} = {01A6D73F-996E-48B3-B111-2725016A49C2}
+		{DB4A8A1F-54A8-4534-AE0A-027B365AA73B} = {ABF03698-B81C-45DE-B76A-C7FBC0C72DB6}
+		{2731DE56-AF4B-4009-8259-2EA5A9A102FE} = {ABF03698-B81C-45DE-B76A-C7FBC0C72DB6}
 	EndGlobalSection
 EndGlobal